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How To Diagnose And Replace A Faulty Pressure Relief Valve In A Hot Water Heating System

By Edited Nov 13, 2013 1 4

How To Diagnose And Replace A Faulty Pressure Relif Valve In A Hot Water Heating System

 

How To Diagnose And Replace A Faulty Pressure Relief Valve In A Hot Water Heating System, is an article that homeowners will be happy to find. Saving hundreds of dollars and performing this repair yourself is a very tempting opportunity. Learning what the functions of the pressure relief valve are is a necessity before you start to work on one.

What Does A Pressure Relief Do?

Pressure relief valves are installed in boilers and water heaters. They are specifically designed to go off and relieve any extensive pressure that can build up in this type of equipment for a variety of reasons.

Hot water heating systems will use a 30 pound per square inch pressure relief valve to obtain the safety level they wish to maintain within the system. This means that a hot water heating system pressure relief valve will go off and release water when the pressure exceeds 30 pounds.

Hot water heaters employ a 100 pound per square inch pressure relief valve and this valve is also an overheating safety as it is a combination temperature and pressure relief valve. One of the reasons that the pressure is higher on this equipment is due to the higher pressure in domestic hot water tanks compared to hydronic heating systems.

So on both types of heating apparatus, the pressure relief functions to let water blow off and allow resulting pressure reduction to keep the system safe from over pressurizing and causing damage to itself or the property around it. This is why it is so imperative that any faulty pressure relief valve be changed immediately upon discovery.

Tools Needed To Change Your Pressure Relief Valve

Channel Lock Pliers (39198)

Channel lock pliers could possibly be the only tool you need to perform this repair. If you don't happen to own a pair they are available from Amazon.com. A roll of plumbers teflon tape and some pipe thread compound will be needed, as well as a rag to wipe down the job when you are done. Some pressure relief valves will be very difficult to remove on older systems and these may require the use of a pipe wrench to get the old one out.

Parts Needed To Replace A Leaking Pressure Relief Valve

Pressure relief valves

Most of the time all you will need to have on hand will be the actual replacement valve. Get the numbers off the tag from the one that is faulty and match this up at the supplier. Getting the right valve for your application is imperative. All pressure relief valves are available at local plumbing and heating supply outlets and most home improvement stores. They are also available from larger hardware stores and also Amazon.com

Removing The Existing Faulty pressure Relief Valve

When we start out to change this valve, the first thing that must be done is to remove any pressure that may be on the system. Start out by locating and shutting off the power switch to the system. this is usually located on or near the boiler and will have a red cover on the switch plate. After the power is off, shut off the water supply to the system. Let the system cool off as much as possible to negate the risk of injury from being scalded with hot water.

Once the system has sufficiently cooled, close any auto vents that are installed in the piping or boiler. Then a bucket can be used under any drain in the boiler area that will relieve the system pressure.

Very little water will come out, maybe a half gallon to a gallon depending on the size of your system. The rest will remain in the system due to the air tight vacuum that has resulted from draining the water out of the boiler drain.

Once the pressure has been relieved and the water stops coming out of the drain, close the valve tightly and we can proceed to remove the valve.

Pressure relief valves have a pipe coming out to discharge any water at a safe location and this pipe must be removed first. Unthread the outlet pipe and remove it from you existing pressure relief valve. Now grasp the pressure relief with your channel locks and remove the valve. You may get a very small quantity of water so take precautions around you with property.

Installing Your New Pressure Relief valve

Installing your new pressure relief valve is exactly the opposite of what you just did. Use several wraps of teflon tape, being sure to go in the right direction on the threads so the tape will not wind off when you tighten the fitting. Also apply a small amount of pipe sealant compound to the threads over the tape. start the valve into it's position and tighten as much as possible by hand. Now use your channel lock pliers and tighten the pressure relief valve very tightly and end up in the position of the old one.

Now you can reinstall any piping that safely lets the water out away from anything that it can damage. Once this has been reinstalled the system is now ready to put back into regular operation.

Refilling The System After Changing A Faulty Pressure Relief Valve

Refilling your hot water heating system after replacing a pressure relief valve is as simple as turning the water back on. Hot water heating systems normally employ a automatic feeder to maintain the proper pressure so the simple act of opening the feed will bring the system back to it's normal operating pressure. Once the system pressurizes which should happen somewhere between 12 and 25 pounds on your boiler guage, you are now ready to return power to the unit by turning on the shutoff switch we turned off when we began. Your system is now ready for operation and will fire if there is a call for heat.

Check around the repair for any leaks and if none are present you finished and you are back in business and you just saved a several hundred dollar service call to the plumber. Hopefully How To Diagnose And Replace A Faulty Pressure Relief Valve In A Hot Water Heating System, has given you the insight to undertake this task.

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Comments

Jan 26, 2011 11:25am
JackLTrades
Great advice, this can be a tricky job but you have got it covered
Jan 26, 2011 11:27am
dreamaker
Yes it can but most can handle it. Hopefully at least a couple people can save a few bucks. Thanks much for the visit.
Mar 9, 2012 6:08am
JadeDragon
just the right info for the value problem
Mar 9, 2012 8:10am
dreamaker
Thanks Jade Dragon, and thanks for the visit.
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