Tag Archives: plumbing

Anti-scald valves

Anti-scald valves, also known as tempering valves and mixing valves, mix cold water in with outgoing hot water so that the hot water that leaves a fixture is not hot enough to scald a person.

Facts and Figures

  • Scalds account for 20% of all burns.
  • More than 2,000 American children are scalded each year, mostly in the bathroom and kitchen.
  • Scalding and other types of burns require costly and expensive hospital stays, often involving skin grafts and plastic surgery.
  • Scalding may lead to additional injuries, such as falls and heart attacks, especially among the elderly.
  • Water that is 160º F can cause scalding in 0.5 seconds.

Unwanted temperature fluctuations are an annoyance and a safety hazard. When a toilet is flushed, for instance, cold water flows into the toilet’s tank and lowers the pressure in the cold-water pipes. If someone is taking a shower, they will suddenly feel the water become hotter as less cold water is available to the shower valve. By the same principle, the shower water will become colder when someone in the house uses the hot-water faucet. This condition is exacerbated by plumbing that’s clogged, narrow, or installed in showers equipped with low-flow or multiple showerheads. A sudden burst of hot water can cause serious burns, particularly in young children, who have thinner skin than adults. Also, a startling thermal shock – hot or cold – may cause a person to fall in the shower as he or she scrambles on the slippery surface to adjust the water temperature. The elderly and physically challenged are at particular risk.

Anti-scald valves mitigate this danger by maintaining water temperature at a safe level, even as pressures fluctuate in water supply lines. They look similar to ordinary shower and tub valves and are equipped with a special diaphragm or piston mechanism that immediately balances the pressure of the hot- and cold-water inputs, limiting one or the other to keep the temperature within a range of several degrees. As a side effect, the use of an anti-scald valve increases the amount of available hot water, as it is drawn more slowly from the water heater. Inspectors and homeowners may want to check with the authority having jurisdiction (AHJ) to see if these safety measures are required in new construction in their area.

Installation of anti-scald valves is typically simple and inexpensive. Most models are installed in the hot-water line and require a cold-water feed. They also require a swing check valve on the cold-water feed line to prevent hot water from entering the cold-water system. They may be installed at the water heater to safeguard the plumbing for the whole building, or only at specific fixtures.

The actual temperature of the water that comes out of the fixture may be somewhat different than the target temperature set on the anti-scald valve. Such irregularities may be due to long, uninsulated plumbing lines or defects in the valve itself. Users may fine-tune the valve with a rotating mechanism that will allow the water to become hotter or colder, depending on which way it’s turned. Homeowners may contact an InterNACHI inspector or a qualified plumber if they have further questions or concerns.

In summary, anti-scald valves are used to reduce water temperature fluctuations that may otherwise inconvenience or harm unsuspecting building occupants.

by Nick Gromicko, InterNACHI

Originally posted 2018-04-06 18:41:56.

Bathroom sink draining slow?

We ask a lot of our bathroom sink drains. We pour toothpaste, soap, shaving cream, makeup and stray hair into them and expect them to work. Unfortunately, sometimes they don’t. A serious clog usually requires a chemical drain cleaner or a plumber’s snake. For a slow-moving drain, you might first try a plunger to dislodge the clog. It’s easy to use; be sure to use it carefully and avoid splashes. Before you begin, put a few inches of water in the sink to provide a good seal around the plunger. Next, stuff a wet rag into the overflow opening of the sink and seal it well. This air block greatly increases the effectiveness of the plunger. Then plunge away! You may have to refill the basin with water a few times to free a very stubborn clog.

Originally posted 2018-03-23 08:06:39.

VIDEO: Saturation under and around toilet

At a recent home inspection on Orcas Island, I discovered water stains around a toilet that the Seller informed us were “historic.” Probing with a moisture meter, it was clear that the subfloor was clearly saturated with the possibility of underlying damage not visible without pulling the toilet and invasively inspecting. Moisture meters and infrared thermography help home inspectors determine elevated moisture conditions not visible to the naked eye.

Originally posted 2018-01-22 09:00:35.

VIDEO: Broken toilet valve

Testing a toilet at a recent home inspection on San Juan Island, I couldn’t get it to flush. So, I removed the tank lid and attempted to open the valve to verify it actually flushed. In this video, you see the valve/stopper basically come off in my hands, but it flushed! If your toilet valve is tight or non functional, it’s a pretty easy repair. Universal toilet valve repair kits are available at most hardware stores; if you have a specialty toilet, you can check with your plumbing contractor and/or search online for replacement parts. I like Amazon.com because I can get parts quickly shipped to my door.

Originally posted 2018-01-15 11:00:59.

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Polybutylene plastic plumbing supply lines (PB2110) were installed in a house at a recent home inspection in Oak Harbor on Whidbey Island.  Polybutylene has been used in this area for many years, but has had a higher than normal failure rate, is no longer being widely used, and has been the subject of class-action lawsuits. Copper and Brass fittings used in later years have apparently reduced the failure rate. This particular house has copper fittings and PB2110 supply piping.  More information about PB water supply piping can be round at http://www.pbpipe.com.

Originally posted 2017-06-09 08:00:29.


Every month, we seek to bring our readers insight from the worlds of home construction, home repair, and home maintenance straight from local Northwest Washington contractors in a segment we call “3 Questions.” Yep, you guessed it: we ask three questions, and the contractors answer them. This month, we learn about structural issues with Dale Kimber, president at Bay Point Plumbing.

Q1: A “Johnson Tee” is another way to vent a dishwasher drain which is somewhat common in the Seattle area, but less common in our local area. Can you tell us about the “Johnson Tee” and if you like this method of vent for dishwasher appliances?

Johnson tees have been used to protect homeowners from drains back-siphoning sewage into appliances like dishwashers and clothes washers. Johnson tees are less commonly used as they are an “old school” method. Johnson tees can only be installed when U.P.C. listed as an approved fitting. 

Here at Bay Point Plumbing, we prefer to protect dishwashers and clothes washers by using physical air gaps and/or approved air gap dishwasher fittings. Always consult with your local jurisdiction about their provisions on the code (See the paragraph below).

The Uniform Plumbing Code section 807.4 of the uniform plumbing code states: “No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an Approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood-level [FL] marking at or above the flood level of the sink or drainboard, whichever is higher.”

Q2: Can you tell us about AAVs or Air Admittance Valves? In what general situations would one use such a device?

Air Admittance Valves are not allowed in most jurisdictions. They can be used in Island County and Anacortes city limits. AAVs are typically used to substitute installing a vent pipe from one sink to the outside air. AAVs should be installed in a vertical manner, 4” above the p-trap weir, and 6” above its highest flood level rim. 

Bay Point Plumbing does not like to install Air Admittance Valves as they are a mechanical device that will eventually fail. We install pipes venting directly to the outside air and contain no mechanical components.

Q3: New technology uses “Push-On” connectors to easily and without tools join PEX, copper, CPVC water supply piping. Is this a good route for DIY homeowner-plumber?

Push-on connectors are great for homeowners connecting to old copper piping, CPVC piping, or polybutylene piping. Most Push-on connector manufacturer’s warranty their products for 25 years which will usually exceed the life of the mentioned above. Make sure you have a push-on connector specifically designed for the material of piping that you are using and following the manufacturer installation instructions.

Bay Point Plumbing does not recommend using Push-on connectors when joining PEX-to-PEX, because the push-on connector will probably not last as long as PEX fittings.

About Bay Point Plumbing

In 1989, Gary Jones founded what would become Bay Point Plumbing while working out of his home. Gary’s goal was simple: to bring much-needed professional plumbing and mechanical services to Whatcom County, Wash., and the surrounding areas, Bay Point Plumbing employs a whole team of expert, certified, and licensed technicians. Gary’s philosophy was to work exclusively with the area’s best technicians, recruiting local talent to fill out his crew. This expansion led to the hiring of Dale Kimber, a certified plumber. Dale brings years of industry experience to the job and holds certifications in plumbing, gas fitting, pipefitting, and backflow testing. Under Dale’s expert guidance, Bay Point Plumbing has continued to expand to deliver on Gary’s vision. For expert commercial and residential plumbing and mechanical services, contact Bay Point Plumbing today at https://baypointmechanical.com/.

A big “thanks” to Dale for his responses!If you have questions or comments about plumbing issues or home inspections in general, tweet me (@AIHomeInspect).

VIDEO: Overflowing Air Gap

Water coming out the air gap should not be a regular occurrence, though occasionally it might happen when, for example, someone forgets to run the garbage disposal. Regular water discharge from an air gap points to a restriction in the water flow that should be further evaluated and repaired. This video was taken at a recent home inspection in Friday Harbor on San Juan Island. Continue reading

Originally posted 2017-02-27 10:04:51.