Hot water heater pressure relief valve

[Raspy]

Originally Posted by Bob_SWCO

Reace (Escape Trailers) told me they started installing check valves on the inlet side of the water heaters primarily to protect the weak check valves that are integral to the water pumps they use. Beyond damaging the check valves in the pumps, he also said owners sometimes experienced leaks from the toilet inlet valves when the WH cycle raised water pressure throughout the trailer. I have read posts from owners who experienced other cold-water-side leaks (under sink faucet connections, etc.), when they did not have a check valve isolating the cold water supply side from the WH.

Sounds like they were applying the wrong fix. If there was a pressure problem caused by the water heater, the fix is an accumulator, not a check valve. In your case, with an installed accumulator, why not just take out the check valve? Or defeat it by taking the guts out if that's easier. Or drill a small hole in it as I suggested.

I'm not saying Escape doesn't know what they are doing, but so often, people don't understand the simple physics of this kind of problem, or they resist the need for another part by saying "a leaking pressure relief valve is normal". In this case normal doesn't mean correct, or safe, it just means that most of them leak because there is no other allowance for expansion. The reliefs are doing their jobs and not failing, but the set pressure is much higher than the system should experience. Escape's attempted fix, their pump problems, your experience, other's experiences with leaking relief valves and my experience, all bear this out.

[Roamer]

Not ure what is meant, disconnect.

These valves are the same as your home units? So, should be the same you can get at hardware store. Are there different pressure rating available, sounds like RV might need lower than a house. I just looked at mine today, a 2005, and thought maybe just replace it for safety. Your house one is supposed to be replaced every year or two or three.

The fix is turn on hot faucet for a split second to relieve pressure. Bam. I think you will do that when showering anyway.

On my boiler I know in the summer 8 minutes, winter 12 minutes and I can use straight hot water for a warm shower, not fiddling with both cold and hot to get a temp I like. I only heat water for a shower - heat it, turn off heat, then shower. works for single occupancy/single shower.

If Im plugged in then I usually just keep the 120 on and water hot.

The safety valve, near top, is meant to open (not leak) at preset pressure so the tank does not explode. This will not hurt the valve, and you may open the valve yourself and watch water run out at your pleasure. You ARE supposed to "test" it periodically this way anyway, per instructions.

Side note: At home you SHOULD open the drain valve at the bottom manually and let the water flush out debris (rust and dirt) with it. I do about a gallon every month or so. Actually use it as a source of water in basement - perfectly safe and recommended. This will make the thing last longer. RV'ers do the drain every winter so that is sufficient for RV tank flush.
At home my safety valve is plumbed to run to the outside, so opening it will help keep the pipes flushed out in case there is a real release of pressure.

[Jann Todd]

Originally Posted by BatDude

New lesson for me…We have been turning off our water heater after each use in order to conserve propane. Our new Escape has the 110 VAC/propane 6-gallon water heater. Temp is factory preset so really hot.

We have been camping in arears with dirt/grass sites like the 31 days at Jekyll Island so did not notice what I perceived a few days ago as a water issue. Out Topsail State Park in Florida was on a nice concrete pad, very level. When disconnecting I noted a small wet area under the water heater area. Me thinks YIKES!

So, I kept an eye on this and at first assumed that I had not used sufficient Teflon tape on the anode rod I removed to drain the tank to avoid freezing before we departed on our trip. So, I removed/replaced the anode again with an extra layer of tape this time. Although I used the standard amount the first time.
For the next two nights we stayed single nights on our way west at places with concrete pad. Again, I could see a wet spot under the water heater. When I opened the water heater hatch cover, I could see the water was dripping from the pressure relief valve. Oops.
Quick call to Escape and Dave the parts/serv ice guy called back about an hour later. Ahem …after I rushed to an RV supply store 5 miles away from tonight’s one-night park and stop and spent $29 for a replacement.
Dave called back just as I was about to remove the pressure relief value on the unit and educated me that these water heaters will always drip to relieve pressure when the heater is continually turned on and off. Better to leave it on the entire time (electric). Every time one disconnects and re-connects some air gets into the system. It expands as the water is heated so pressure is relieved by the safety value.
Lesson learned from now on when we connect, I will use the 110 VAC to heat the water and leave it on all night.
The assumption is that for a longer time it is on it will only leak at first heat up and expansion,
Never noted that issue with eh smaller Scamp propane heater, but apparently normal for the 6 gal Suburban gas/electric heater.

Every day is a new learning event!


Cheers,
Bat Dude

We have the 110/propane hot water tank in our Casita. If on shore power we leave it turned on all the time. If on propane we turn it on when we need to wash dishes or clean up. We always use a pressure regulator on our hose at the faucet itself. Most parks have much to high of water pressure. This can break your water lines. We've had a few regulators go bad so invest in a fairly decent one. We've also went out and lifted the little lever for a nano second to release pressure. Be careful as the water is hot. Seems this helps. We also lift it for a few seconds when we fill the tanks before a trip. This way the water is not hot and will wash out any debris in the valve. We pull out the anode rod and flush the tank at least once a year or anytime we know we've been in some bad water to prevent a build up of debris. I think just good practice as maintenance and to keep your tank in good condition. So far we've never had to replace a valve in the water tank. Our tank is also one that does not have a way to set the temperature.

[Glenn Baglo]

Originally Posted by Jann Todd

We've also went out and lifted the little lever for a nano second to release pressure.

That is the purpose for the existence of the valve - to relieve excess pressure.

[John in Santa Cruz]

when I leave my water heater on, once its heated up, it only runs for a few minutes a couple times a day to keep the water hot, thats really not that much propane usage.

I shut it off when I'm packing to travel.

[Raspy]

As I mentioned before, I find it interesting that people are concerned about the pressure at the faucet where they hook up in parks, but seem to not be concerned about pressure that builds up from the water heater.

If the pressure from the faucet is high enough it will pop the relief valve just the same as the pressure from the water heater. If it does not leak from faucet pressure, but does while the water heater is on, the pressure is higher from heating the water. Pressure is pressure.

A lot of pumps are set at about 40 PSI on and 60 PSI off. To me this is higher than necessary. It won't hurt anything, but can easily lead to more water usage. 30 PSI is plenty unless you are trying to put out a fire. Just for reference, 60 PSI is normal house pressure. 90 PSI is abnormal and will cause early water heater failure. I run my house at 35 PSI on and 50 PSI off. That is plenty for drenching showers and good watering outside. My trailer pump seems to cut off at about 45 PSI. The regulator that I connect to park faucets, that feeds my shore tie hose, is set at 35 PSI. Plenty of pressure.

The only problem with testing your pressure/temperature relief valve (P&T) is that they will sometimes get a piece of debris under the seat and continue to leak. Fix this by lifting the handle momentarily and letting it snap back closed. You might need to do it a couple of times. This will clear it and let it seal.