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Troubled Houses - The Home Owner's Resourcesm - Plumbing

We see many interesting adverse conditions during our inspections, partly because of the unlimited number of ways people can mess up a house, but also because we do a thorough inspection to reveal these adverse conditions. We hope these stories and illustrations help home owners avoid these costly conditions by learning about causes, preventions, and remedies. A home purchase can create opportunities for the new owner to improve the home, possibly increasing its value, durability, and usefulness.

NOTICE TO BUYERS & SELLERS: This site does NOT encourage or discourage the purchase of any individual house, or style, age, location, or condition of house.  Conditions shown and/or described in the following articles may have been remedied at the house where these conditions were found.  These conditions typically can be remedied by qualified contractors. The presence of these conditions in any house is comparable to any other real estate consideration such as price, size, or location.  Consult a qualified home inspector before purchasing any house, and consult a qualified real estate agent for more information on how to handle a real estate transaction where adverse conditions are reported in a home inspection.   This site does not describe any house by address or knowingly show a readily identifiable exterior image.  Further, no home actively listed for sale  will be described on these pages at the time the article is posted.

THANK YOU for visiting   
Learn more about our services, which now include IR Thermography, radon testing, and carbon monoxide tests. All photos copyright Roger Hankey. . All rights reserved. Licenses to use these copyrighted images can be arranged by contacting

"Troubled Houses - The Home Owner's Resource" is a SERVICE MARK of Hankey & Brown Inspection Service Inc.   List of topics and all articles in this resource. (Also includes Photos of the Month.)

Plumbing topics
Abandoned water wells are required to be sealed.

Floor drains
    Plumbing matters (Water service pipe)
   Warning - What warning? (Dryer vent)
   Size Matters (Trap depth)
   Un-Truth in Sale of Housing (Sewer gas entry)
   Water heater venting (wrong from the start)
   Water heater venting  (An orphaned water heater)
   Sewer gas delivery system (Humidifier drain hose) 
   The Pits (Sewer cleanout extension)
   Trap missing - Sewer gas entry point  (laundry standpipe)
   Lack of maintenance & knowledge 
(Garbage disposers improperly installed & used)
Does your dryer vent work?   
   Gas Piping Change or Appliance Replacement - Let a plumber do it!
   Clogged arteries in your house (old steel water pipes)   

             Abandoned water wells are required to be sealed.

Minnesota law requires that real estate transactions include a water well disclosure.  If a well is present on the property it must be disclosed.  Further, if the well is not in use, it is considered an abandoned well and  must either be properly sealed by a licensed well driller, or made functional. 

Home inspectors occasionally encounter abandoned wells that have not been sealed.  This occurs when property owners have been on city water for years, abandoned the well years ago, or failed to maintain a well that had been repurposed for irrigation after the city water service was installed. 

In these cases, the well head is often a hidden or out of the way place that owners or real estate agents ever check.   Two cases are shown below.

 Abandoned water well, unsealed. (C) 2014 ASHI Certified Inspector Roger Hankey Winter Park, CO
This abandoned unsealed well was hidden below the floor in a crawl space. Note the equipment still in place.

 Abandoned water well, unsealed, pipes still on well head. (C) 2014 ASHI Certified Inspector Roger Hankey Winter Park, CO
This unsealed well was in the old pump space under a front entry stoop.  Note pipes on wellhead. 

Former water well, sealed, all pipes removed from well head. (C) 2014 ASHI Certified Inspector Roger Hankey Winter Park, CO
         Properly sealed water well.

The well head shown here has had all pipes removed leaving only the well casing.  A look into the casing shows the well is filled with concrete grout. This prevents any foreign materials or fluids from entering the well.  Proper sealing is important to protect the aquifer that the well penetrates. 

The Minnesota Dept. of Health Well Management Unit regulates the drilling and sealing of water wells.  They also maintain records of each well in the state.

Information on the status of a well can be found by calling the well management unit at 651 201 4600 or 800 383-9808.

Click here to read the Minnesota Dept. of Health (MDH) document on Wells at Property Transfer.

Click here to read the MDH document on Abandoned Wells.

Costs to seal a well vary depending on the depth of the well and its accessibility.  Typical costs range from $500 to $1,000 and are typically the responsibility of the property owner.  Your county health department may know if the property in question qualifies for any government aid help pay for the cost of well sealing.  



Floor Drains - A potential sewer gas point of entry

Older homes with basements often have cast iron floor drains near the laundry, furnace, boiler, or water heater.  This style of floor drain is also found in some basement shower stalls.  These drains usually had a threaded cleanout plug which is often not re-installed after the drain is cleaned.  If the plug is not screwed tightly back into place, the drain is open to the sewer, and the threads rust away.  Without the plug in place, the drain is no longer protected by the water seal trap and sewer gas can enter the house via the cleanout.

Floor Drain drawing typical in Minneapolis houses


       Old iron floor drain without cleanout plug. Troubled Houses photo copyright 2010     Old iron floor drain with Real-Tite Plug in cleanout. Troubled Houses photo copyright 2010, ASHI Certified Inspector in Winter Park, CO

       Drain without cleanout plug                  Drain with plug, and a high water level

   Click here for more information on Real-Tite Plugs.

Plumbing Matters

Old steel water service - limits water flow to house.  (C) 2010,  ASHI Certified Inspectors, Winter Park, CO

     This house had new water pipes on the house side of the water meter, but unfortunately it still had very low water flow.  The flow was limited by the old galvanized steel water service from the meter out to the city water main.  Replacement of this water service pipe is needed to finish the job of improving the water flow to this 80+ year old house.  The cost of replacing the water service are likely to be $4,000 to $6,000.

Warning? What Warning?

 Troubled Houses photo of plastic vent for clothes dryer. (C),2010  ASHI Certified Inspectors in Winter Park, CO

This gas clothes dryer is vented with a flammable flexible plastic tube.  The bright yellow label on the back of the dryer (detail shown below) clearly states that the manufacturer does not recommend use of a flexible plastic duct.  Obviously the duct installer ignored the label warning.  Notice the heat scorch marks on the back of the dryer just above the vent connection.  The gas connection is also an unapproved flexible brass connector.

                           Troubled Houses photo of clothes dryer vent duct warning label. Roger Hankey, ASHI Certified Inspector in Winter Park, CO

 Size matters - or Deeper is not always better

The kitchen sink shown here was part of a kitchen remodeling in a 1950's rambler. The new sink is extra deep, for washing large pots. Unfortunately, the installation created a condition which increases the potential for clogged and leaking drains, especially since it will receive food waste from the disposer.  The extra depth of the sink created an extra deep trap (more than twice as deep as normal) with a water level above the joints in the trap.  Our report recommended this condition be corrected by a qualified plumber since the plumbing in the wall will likely need to be altered to accommodate the depth of this sink.

                                Troubled Houses, Deep trap on kitchen sink, (C) 2010, ASHI Certified Inspector in Winter Park, CO

"Un" Truth in Sale of Housing 

  Water meter over pit in floor Troubled Houses Photo (C) 2010 ASHI Certified Inspectors, Winter Park, CO           Troubled Houses, Damaged sewer cleanout cover in pit. Photo (C) 2010, ASHI Certified Inspector in Winter Park, CO

The Minneapolis "Truth in Sale of Housing" report for this 1925 house done two weeks before our inspection did not identify a significant adverse condition that if reported properly would have been a "Required Repair". We reported that the main sewer pipe, which passes through the former water meter pit, was damaged at its cleanout opening. (detail photo below)  The damage created an opening which permits sewer gas, and possibly rats, to enter the house.  Repairs to the pipe may require a replacement of a portion of the cast iron sewer pipe.  The "Truth in Sale" evaluator is required to examine this area, to identify the type of main water pipe.  Lifting one small board reveals the pipe.   The evaluator reported that the water pipe was not visible and that the sewer pipe "Meets Minimum Requirements".  The evaluator also reported the attic as "not applicable".  We easily examined the attic from a step ladder.

                                Troubled Houses, Damaged sewer cleanout cover in pit. Photo (C) 2010, ASHI Certified Inspector in Winter Park, CO 

Home buyers are advised to not rely on these city reports as they frequently do not identify adverse conditions and do not require the evaluator to open the electrical panel, or use a ladder to examine the roof.       Return to plumbing topic list 

                      Water heater vent connection - Wrong from the start

                Water heater and furnace vent. Troubled house photo (C) 2010, ASHI Certified Inspector in Winter Park, CO 80482         Side view of Water heater and furnace vent. Troubled house photo (C), ASHI Certified Inspector in Winter Park, CO 80482

At first glance this 7 year old water heater vent seems normal.  It connects to the furnace vent with a saddle "Y" connector.  Even from a side view - shown at right - it looks reasonable.  Not until you look close at the top of the water heater does the trouble become evident.  When the heater's burner is ON, fumes spill out of the heater's draft hood.

                             Detail of water heater, not venting. Fumes spill at draft hood. Troubled house photo (C) 2010, ASHI Certified Inspector in Winter Park, CO 80482

Clearly there has been severe overheating at the top of the heater. The plastic rings around the water pipe connections are BURNT away and the white paint at the top is very scorched.  A close inspection reveals that the vent diameter is 4" while the opening at the top of the heater is 3".  Further, the vent connector consists of two elbows.  The furnace in this installation vented properly, and the vertical and horizontal vents were NOT obstructed.  Proper venting depends on proper sizing, smooth transitions, and connections which do not create turbulence in the vent.  A resized vent connector installed into a tee fitting ABOVE the existing furnace vent will probably work well. See example shown below.  The existing water heater vent is spilling its combustion fumes into the house and is an adverse condition.  We recommended immediate correction by a qualified plumber.

                              Ideal water heater & furnace vent connections. (C) 2010, ASHI Certified Inspector in Winter Park, CO 80482

Water heater venting - The orphaned water heater.

Melted rings at top of a gas water heater.  Troubled Houses-The Home Owner's Resource. (C) 2011 ASHI Certified Inspectors in Winter Park, CO

Gas water heaters are the second most common gas fired equipment in Upper Midwest homes (after furnaces).  When checking natural draft water heaters it is important to look for indications that the exhaust gases (mostly carbon dioxide and water vapor) are not all passing up and out the vent connector to the chimney.  The plastic rings around the water pipe connections at the top of this 4 year old heater were melted, as was the bottom of the plastic insulation sleeves.   A test for carbon monoxide was conducted and slightly elevated levels of carbon monoxide were being produced (65 ppm CO "as measured").

Carbon monoxide test of a gas water heater.  Troubled Houses-The Home Owner's Resource. (C) 2011 ASHI Certified Inspectors in Winter Park, CO  
Also notice that the vent connector begins with a 90 degree elbow rather than a short section of vertical vent, then runs about 3 feet back where it turns again.  The photo below shows the rest of the vent which ran behind the direct vent gas furnace.

Excessive increase in the size of a vent connector for a gas water heater.  Troubled Houses-The Home Owner's Resource. (C) 2011 ASHI Certified Inspectors in Winter Park, CO
Here is the remainder of the vent connector.  We see the third elbow which turns the vent to the chimney, and 3 fittings which increase the size of the vent diameter from 4" to 8" where it connects to the chimney liner.  The 8" liner once received both the water heater and the former old gas furnace.  The current furnace is a high efficiency sealed combustion model which vents out the basement wall via a small plastic pipe.  The water heater is the only appliance venting into this 8" flue. This change from furnace & water heater sharing a vent sized for the furnace to venting the water heater only is often referred to as an "orphaned water heater" since the larger appliance is no longer connected to the vent.  The water heater is designed to vent into a 4" vent.  This size vent if used, would keep the combustion products warm during their passage up and out the chimney by the natural draft of the rising gases.  Unfortunately in this case, the 3 elbows in the vent connector created equivalent of 30 feet of horizontal vent resistance to flow AND the large size of the chimney liner allowed the combustion gases to cool quickly, losing the energy needed to rise up and out the chimney. 

This adverse condition was serious and immediate correction by a qualified plumber or HVAC firm was recommended.    Installation of a smaller chimney liner, and reducing the amount of vent elbows will probably be needed to reduce the potential for combustion gas spillage. 

Sewer gas delivery system

Most central humidifiers, typically installed on the return air plenum (main duct) of forced air furnaces, utilize a continuous trickle flow of water through the system when operating.  Therefore, the humidifier must have a drain hose to convey the excess water out of the humidifier.  Typically this hose runs to a nearby floor drain.  In cases where a floor drain is not present near the furnace some do-it-yourself installers look for creative ways to drain away this water. The photo below shows one method.
   Drain hose from central humidifier on furnace runs to sewer cleanout.   Troubled Houses-The Home Ow (C) 2012 ASHI Certified Inspectors in Winter Park, CO 
The DIY installer saw that the main waste pipe sewer cleanout cover was in the furnace room.  They drilled a hole in the cover and installed a tap in the center of the cover. (detail shown below). The foil covered duct in this photo is a make-up air or combustion air duct.
                Detail of drain hose from central humidifier connected to a sewer cleanout.   Troubled Houses-The Home Ow (C) 2012 ASHI Certified Inspectors in Winter Park, CO
When the furnace is in operation, the return air plenum -and the humidifier - are under suction (negative air pressure) and can pull sewer gas through the green hose into the circulating air of the home.  Our recommendation in this case was to replace the sewer cleanout cover, and install a condensate pump beneath the humidifier to pump the excess water to the laundry sink in an adjoining room. 

               Improper laundry drain is a sewer gas entry point

The waste hose from this clothes washer discharges into what at first glance looks like a proper standpipe drain.  A closer look reveals that the standpipe is connected to the waste and vent pipe with a a tee and elbow only, NOT a trap.  There is no water seal between the open end of the standpipe and the drain.  This is a sewer gas entry point.  A qualified plumber should be able to make the correction (install a trap and revent) readily since the pipes are exposed.

    Laundry standpipe drain with no trap. (C) 2012 ASHI Certified Inspector in Winter Park, CO

                                                      The Pits.

Thousands of older homes in Minneapolis have exposed soil in the basement that has the potential to introduce excess moisture and radon into the house. The exposed soil is located in a pit about 20 inches square and about a foot deep. When these pre-1930 homes were new, the water meter was buried in sand in this pit, since the basement could occasionally get quite cold if the furnace or boiler was not stoked with coal.

The development of modern thermostatically controlled heating (In large part by Minneapolis Honeywell) eliminated this potential freeze up of the water meter. As meters were modernized and old iron water services replaced with copper, nearly all meters have been raised out of the sand pits.
(C) 2012 Water meter pit with exposed damp soil and decayed wood frame. Roger Hankey Certified ASHI  Inspector Winter Park, CO

The sand pit also typically contains the access or cleanout plug for the main sewer. These are usually visible where the sand has been removed, or just a few inches below whatever sand remains in the pit.
(C) 2012 Water meter pit with exposed damp soil and sewer cleanout cover. Roger Hankey ASHI Certified  Inspector Winter Park, CO

If the house has a modern copper water service, it is recommended that the pit be eliminated in 4 steps: 1. remove any wood forms around the pit. 2. have a qualified plumber extend the sewer cleanout cover to a height several inches ABOVE the concrete floor, 3. have an electrician verify that there is a proper grounding jumper around the water meter, and 4. have the pit filled to within 4” of the floor and capped with concrete.

Eliminating the pit will reduce the potential for moisture and radon migration from the earth to the house. Eliminating the pit will permit items to be stored on the floor that formerly was obstructed a wooden pit cover.

Lack of maintenance & knowledge: Garbage disposers misused & improperly installed

Garbage (food waste) disposers are a popular kitchen appliance.  Unfortunately many home owners are not well informed on how to use disposers.  Further, disposer replacement or installation is a task that is often performed by persons who either don't follow instructions or have little understanding of proper plumbing principles.  Kitchen remodeling projects often involve replacing the kitchen sink and/or changing its location. Mis-installation of the drain out of a disposer is common occurence.  The photo below shows the improper slope of a disposer drain.  The reverse slope of this drain will permit water and food waste particles to collect below the dashed red line.

Garbage disposer installed with an improper drain slope. (C) 2012 ASHI Certified Inspector Roger Hankey Winter Park, CO
This improper slope increases the potential for clogging and foul odors.

Another similar installation error is the use of a separate trap "A" in the disposer drain, in SERIES with an existing trap "B".  This also increases the potential for clogging since the food waste and water will be slowed as it passes through the complex set of multiple fittings.  Proper installations often use a "Y" fitting at the sanitary tee in the wall to permit each basin to flow direct to the drain without passing through a second trap.
Garbage disposer installed with an improper double trap in its drain. (C) 2012 ASHI Certified Inspector Roger Hankey Winter Park, CO
Nearly all disposers must be properly grounded unless they are double insulated.  Occasionally both the plumbing AND the wiring on a disposer are incorrect.  The disposer shown below has a no clamp or bushing at to ensure that the wiring is properly secured to the disposer at "C".  Further, the drain arm from the disposer goes to a tee fitting instead of an elbow at "B".  Finally, the disposer has corrosion on the exterior of the grinding chamber at "A". (Discussed in detail at the end of this article).
Disposers, and other manhy devices require a proper clamp and bushing to secure the cable and to prevent the sharp edges from damaging the insulation on the conductors.  The disposer shown below lacks such a clamp and bushing at "A".
Garbage disposer installed without a cable clamp and bushing. (C) 2012 ASHI Certified Inspector Roger Hankey Winter Park, CO
The above image also shows the location of socket in the end of the motor shaft at "B".  This is found on many disposers and permits the use of an allen wrench to rotate the shaft to free up a jammed disposer.  The red button shown at "C" on the bottom of the disposer is a reset button for the disposers internal circuit breaker.  Pushing the button in will restore power to the disposer.

Proper use and maintenance is necessary to reduce the potential for corrosion in the grinding chamber of the disposer.  Decaying food particles not flushed from the grinding chamber can form acids which can eat away the die cast "pot" metal found in the case of many lower cost disposers.  It is essential that the disposer grinding chamber be flushed with water after each use.  Some manufacturers have additional maintenance recommendations including the occasional grinding of ice cubes in the disposer. See the owner's manual for details.  The photo below shows a typical pattern of corrosion from failure to flush the grinding chamber. The connection nipple for the gray dishwasher waste hose is also vulnerable to corrosion from the strong detergents used in dishwashers.
  Garbage disposer with extensive corrosion at the grinding chamber. (C) 2012 ASHI Certified Inspector Roger Hankey Winter Park, CO

                    A rare but extreme case of disposer corrosion is shown in the below.   

                 Garbage disposer collapsed due to corrosion at the grinding chamber. (C) 2012 ASHI Certified Inspector Roger Hankey Winter Park, CO
Most disposer manufacturers make several models.  The more costly models use corrosion resistant materials such as stainless steel in the grinding chamber and have more powerful motors.

Finally, most plumbers and onsite waste treatment system installers do NOT recommend the installation or use of food waste (garbage) disposers on homes connected to septic systems. They advise keeping undigested food waste out of the septic system.  

Return to plumbing topic list 

                            Does your dryer vent work?

Home laundry facilities have changed dramatically in the past 60 years. A wringer washer and concrete tubs in the basement with clothes lines outdoors or hanging from the floor joists are old memories for people born before 1960. Early automatic clothes washers and dryers were also in unfinished basements near the foundation wall and existing plumbing. Dryer vents ran up and out through a basement window or the wall rim below the subfloor.

Modern trends have moved the laundry to the main floor or upper floors, often away from an outside wall. Venting the dryer in these locations can be challenging.

A load of wet laundry contains about a half gallon of water. The dryer must be vented to the exterior to remove this moisture from the home.

Dryer performance depends on a vent that is as short and straight as possible through materials that do not restrict air flow, that do not readily collect lint, and can be cleaned easily. 

Choosing a good location for the laundry, the placement of the dryer and the route of the vent all play a role in the performance of the dryer and the ease of dryer vent maintenance.

 Four types of clothes dryer vents. ASHI Certified Inspectors in Winter Park, CO


Dryer manufacturers know the dangers of dryer fires and label dryers with warnings about vent materials. 
Clothes dryer vent warning label - Never use plastic or nonmetal flexible duct

Installation and maintenance of the dryer vent and its terminal are VERY common concerns found in home inspections. The most common adverse condition found is a loose or damaged vent.

It is essential that home owners know the PATH of the dryer vent and the location of the terminal.

Be aware of excess moisture conditions when the dryer is operating, and check the connection to the dryer and observe the operation of the dryer at the vent terminal. It is also important to be aware of long drying times as this indicates a potentially dangerous clogged vent.

 Clogged dryer vent terminal (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO

The duct must connect to a terminal that opens freely, does not restrict air flow, restricts bird nesting and does not readily clog with lint. The type of vent terminal shown at left clogs readily and is NOT recommended.

Vent terminals with 4 one inch flaps work well. Hooded vents that have a full 4 inch hood depth also work. 

The vent terminal location should be readily accessible so that the duct can be cleaned from the exterior.   


The ideal dryer location is immediate adjacent to an exterior wall. Many modern dryers have multiple vent openings (bottom, back, & sides). Good home design and remodeling plans use this fact to help locate the dryer where the vent will be as short as possible. The vent should have a few elbows as possible since typical sectional elbows have the same resistance to flow as ten feet of straight vent.

Unfortunately, dryer vents are not always installed by qualified professionals. Foolish mistakes in vent layout are commonplace.                           
Flexible dryer vent with excessive turns (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO
The vent shown above will not perform well. If the flexible connector had been shortened to about a third its length it could have made one simple bend to connect to the straight pipe instead of 270 degrees of turn. Notice the yellow warning label on the back of the dryer. This dryer probably also had a left side vent that would have permitted it to be positioned nearly tight to the wall.

Vent sections should be connected with heat rated metal foil tape, not cloth duct tape which will fail from heat, and not with screws whose points project into the vent and collect lint.

Many modern homes and apartments have dryer vents that extend up a wall, into an attic, and out through the roof. This configuration creates the potential for several installation errors, maintenance difficulties, and ice dams due to dryer vent induced snow melt.

Dryer vent roof terminal clogged with lint.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO
This type of roof terminal clogs easily and discharges warm air to the roof.

Dryer vent roof terminal melting snow and making ice dam.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO
A similar dryer vent has contributed to the ice buildup in the roof valley.


A new vent terminal known as “Dryer Jack” model 486 may resolve these issues since it rises 5” above the roof and has a large cleanout cover. Available at

Vents occasionally come loose from their connection to the terminal and discharge hot air, moisture, and lint into the attic. Left unrepaired, condensation in winter on the cold roof sheathing can lead to significant water damage to the sheathing.
Dryer vent loose in attic at its roof terminal with lint discharged to the roof sheathing.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO

IR Thermal image of dryer vent loose in hot attic at its roof terminal.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO

This loose dryer vent was found in summer when the attic was hot. The duct roof connection was too far away from the attic hatch to visibly confirm the status of the connection. We operated the dryer on “air fluff” to blow cooled indoor air into the vent and showed by infrared (IR) thermal imaging that the duct was unrepaired.  The blue color in the IR image is the cooler indoor air being blown into the hot attic.

Dryer vents should not penetrate the fire separation wall between a house and an attached garage, and the vent should not terminate in the garage.
Unprotected dryer vent in attached garage.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO
This dryer vent in a garage is subject to condensation, vehicle impact, and penetrates the fire separation wall. If it is to remain, it could be insulated and enclosed in a wood frame and fire rated drywall enclosure, but a better solution would be to determine an alternate path to the exterior.


Dryer vent maintenance is an important home safety task.

  • The lint screen should be checked with each dryer load and visible lint removed.
    (Failure to clean, is the leading cause of residential clothes dryer fires.)
  • Check the vent terminal for clogging or obstructions
  • Look at all accessible portions of the vent for loose joints or damage.
  • Look inside the vent frequently and have a duct cleaning firm remove excess lint.
  • Move the dryer or change the vent if longer than manufacturer’s guidelines.
    (Typically 25 feet or less)
  • If the dryer vents to the roof, check the vent in the attic and the roof terminal.
  • Do not ignore high moisture conditions or excess lint buildup in the laundry.
    (These are signs of disconnected or damaged vents.)
  • Consider installing a dryer vent safety alarm.

Return to the plumbing topic list

Let the Plumber do it! (gas piping)

Piping for residential gas fired appliances and equipment, either natural gas or liquefied propane gas (LP gas), is generally installed by qualified plumbers. Those installations are typically trouble free for years, without concerns of leaks or insufficient gas supply.

Unfortunately, changes in gas piping, even tasks as routine as abandoning or removing a gas fired appliance, are frequently done without benefit of qualified plumbers. Gas piping work done by untrained or unqualified persons may not create an immediate leak or other signs of the increased potential for dangerous release of gas.

One common adverse condition home inspectors find in gas piping is an uncapped gas line.  Uncapped gas pipes are often found in a laundry where a gas clothes dryer has been removed, or replaced with a 240 volt electric dryer.

Uncapped gas line for dryer beside a 240v receptacle.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO   Uncapped soft copper gas line for dryer, valve taped off .  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO  Uncapped steel gas line for dryer.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO


Typically, the uncapped gas line does not leak because a gas valve upstream of the open end is closed. Nevertheless, a dangerous condition is present since there are numerous circumstances which could result in the valve being opened. Even a slightly open valve could discharge enough gas to rapidly create an explosive atmosphere. Click here to read of a recent gas explosion in Beloit, WI.  The simple remedy is to insist that a qualified plumber install a proper cap or plug on any uncapped gas pipe which is still connected to the supply. Home inspectors encountering uncapped gas lines are generally not equipped to make plumbing corrections. Instead, they will leave warning notes on the pipe and attempt to notify persons responsible for the property of the presence of a potentially dangerous condition. Occasionally an outdoor gas appliance is removed without disconnecting the gas line from the source INSIDE the building. Often these gas lines are unmarked and are found penetrating the foundation wall of the house. Again, it is a simple task for a plumber to disconnect and cap off the pipe so that operating the valve will not release gas into the soil or wherever the piping had been terminated.  Shown below are examples of properly capped gas lines.  Brass fittings will typically have brass plugs or caps.

           Properly capped gas line below a valve.             Properly plugged gas line at a tee fitting.


Clothes dryers are also the site of other typical adverse conditions in the gas piping system. Many dryers are installed with a loop of soft copper tubing to facilitate moving the dryer. The dryer must be moved with care such that the loop(s) in the tubing do not become kinked and reduce or stop the flow of gas in the tube. Other dryers may be installed with corrugated flexible connectors. Modern approved flexible connectors are made of stainless steel to resist corrosion, especially from some laundry products. Old flexible gas connectors, often made of brass, are less corrosion resistant, and also can have very thin material at the ends of the connector. The US Consumer Product Safety Commission (CPSC) recommended in October 1996 that uncoated brass gas connectors be replaced with modern materials. For more information, click this link.

Flexible gas connectors. Drawing from Illustrated Home, by Carson Dunlop, Inc.

Approved flexible gas connectors for appliances are NOT intended to pass through a wall or floor without protection. Properly installed gap piping in these instances are typically steel piping, copper tubing, or coated stainless steel tubing (CSST).

Another detail often overlooked by unqualified persons installing gas piping is the installation of a sediment trap, also known as a “Drip tee” or “dirt leg”. This simple piping configuration creates a small trap at the bottom of the vertical leg of a tee fitting. Any sediment, water, or other foreign material in the gas line is like to fall into the trap and not flow into automatic gas control valves that might otherwise malfunction if contaminated with foreign material. 

The dryer gas line shown below has an old flexible brass connector.  It also lacks a sediment trap.


     Drip tee in gas line. Drawing from Illustrated Home, by Carson Dunlop, Inc.  

Soft copper tubing is commonly used for appliance connections, but beware that this material kinks easily unless bent with a special tool.  Kinked tubing may crack and leak or pinch off the line reducing flow to the appliance. 

Use caution when moving an appliance in and out to ensure that the tubing does not catch on an obstacle and kink or pull on the connections.

Kinked soft copper gas line for dryer.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO


Clogged arteries in your house (old steel water pipes)

Many old homes (most of those built before 1930) were plumbed with galvanized steel water pipes. These pipes, typically 3/4" and 1/2" served those homes well for decades.  However, depending on the mineral content of the water, these pipes slowly develop a layer of calcium deposits inside the pipe that reduces the effective diameter of the pipe, and reduces the amount of water the pipe can deliver to the fixture.  There is no practical remedy for removing the mineral buildup inside the pipes.  The reduced water flow may not be noticed for a long time, particularly in a one story house, but when a lower level or basement fixture is in use, a main floor fixture will typically have reduced flow. 

The worst case is occasionally found in old two or three story houses where fixtures on the upper floors receive NO FLOW when water is on at a basement or main floor fixture.

Some home owners attempt to improve flow by having some sections of piping replaced.  This can be a temporary solution particularly for the hot water supply pipes which seem to develop the mineral build up at a more rapid rate.  Unfortunately, a partial repair can create another problem if the replacement copper tubing is connected to the old galvanized steel pipes.   

Connection of galvanized steel and copper water pipes.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO  Connections of copper and galvanized steel pipes can corrode and/or leak, and will corrode more rapidly on hot water supply lines. Further, the act of disturbing the old steel pipes can loosen or dislodge some of the mineral buildup in the pipes which can clog other fittings downstream in the system.


Another common leak and/or corrosion point in old steel piping systems is a saddle type tap for a small flow fixture such as a humidifier or refrigerator ice maker. (Lower right in photo.) These fittings are installed by drilling a small hole in the pipe, and clamping a small probe into the hole. The probe is held onto the pipe with a clamp which "rides" the pipe. There is a rubber seal between the fitting and the pipe.  A small copper tube conveys water from the saddle tee to the fixture. These tees clog readily.  Galvanized steel water pipes and saddle tee fitting.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO


 Galvanized steel water pipes at house side of water meter.  (C) 2013 Roger Hankey ASHI Certified Inspector, Winter Park, CO The water service shown at left has a copper tube coming from the floor which delivers good flow from the city main to the meter, but the piping on the right side of the meter (partly hidden by insulation sleeves) is galvanized steel.  If water flow is limited, we recommend replacing all the piping starting at the house side of the meter.   
Water piping replacements today are often done using PEX tubing (cross linked polyethylene plastic) since PEX tubing is very durable, is flexible, and requires less labor and fewer fittings to install.


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