Water Heater Pressure Relief Valve

So... follow up....

When we returned home from the trip last weekend, I got the water heater up to temperature and then CAREFULLY worked the relief valve on and off for several cycles. Then let it cool down and with the water hose connected, allowed it to flow freely through the valve for a minute or so. Results? No more leaking. Spent this past weekend on another short trip and everything seemed to be working fine. I guess there was just a little calcification built up that needed to be flushed out. I'll keep a check on it and let y'all know if anything changes.

RayChez wrote:

Old-Biscuit wrote:

RayChez wrote:

Rwake901 wrote:
I thought mine was bad too. Read your instructions, according to the instructions a small drip is normal. At least that's what mine say..

They should not leak at all. Nothing normal about having a water leak which would work its way into the sub floor and eventually cause some serious damage.

Normal/not normal.........

More like not uncommon for them to weep.
It is a very small closed system so pressures from swelling of water can cause them to weep and when they do it is outside of rig onto the metal pan. So sub-floor damage is not the usual issue.
Gas solenoid getting wet and then corroding is an issue with Suburban and with Atwood they can weep on the thermal cut-out and/or t-stat terminals corroding them.

So YES they shouldn't leak......but they occasionally do due to loss of air pocket and/or build up of deposits

For eleven years the pressure valve did not leak a drop of water on the water heater on my coach. Then I did not use the coach for about four months and when I fired it up again I noticed that the pressure relief valve was dripping. So I tapped it on the end of the valve stem and it stopped for another month or so. So on my next trip to Pahrump, Nev. while at the RV park I noticed it was leaking again. I figured, well it is just some sediment under the valve, so I figured by tapping it that it would stop. Not this time and it was wetting some electrical components. So I figured that was not good, so I decided to change it out if I could find the part. I checked to see what pressure the valve had to be and I found one at Home Depot. It took me about 15 minutes to change it out. The pressure valve was not even expensive if I recall.

So it is my theory that when those valves leak it is one of two things that has gone bad. Either your water heater is not cutting off when it reaches a certain temperature and it is blowing through the relief valve or the valve spring has lost its tension that it is suppose to have to retain certain pressures.

And yes it does have a little pan and a drain further down, but they are not suppose to leak if the water heater is working properly.

So after eleven yrs. you had to replace.....not bad.
YES as I stated they should not leak but it not uncommon for them to weep due to deposits, lack of air pocket.
Sometimes you just have to replace because they are worn out/weak.

Leaking due to high temps is not common at all due to redundant temp controls.......Normal t-stat 130*F/140*F trip point and ECO/Hi t-stat 170*F/180*F----------T&P set to open at 210*F
So both t-stats would have to fail. That would result in T&P blowing scalding water/steam and heating source still operating.

Quoted from the Atwood Manual--->

( A Pressure Temperature Relief Valve, dripping while the water heater is
running, DOES NOT mean it is defective. During normal expansion of
water, as it is heated in the closed water system of a recreation vehicle,
the Pressure Temperature Relief Valve will sometimes drip. The
Atwood water heater tank is designed with an internal air gap at the
top of the tank to reduce the possibility of dripping. In time, the
expanding water will absorb this air and it must be restored.)

RayChez wrote:

Rwake901 wrote:
I thought mine was bad too. Read your instructions, according to the instructions a small drip is normal. At least that's what mine say..

They should not leak at all. Nothing normal about having a water leak which would work its way into the sub floor and eventually cause some serious damage.

I totally agree with you that they shouldn't leak at all. I'm just telling you what the instruction manual says...

Lots of ideas but ours did this as well $15 for new one and screw it in with plumbers tape and no more drip!!

Try all the simple things that others have suggested first. I play with mine for 2 years and it would work for a while then leak again. I finally replaced it several years ago and it hasn't leaked since. Make sure you get the right size, HD and Lowes did not carry my size, I had to go to a plumbing supply store to get mine. Also yours has probably been in for 15 years so I would used some Kroil oil or PBblaster and let it soak over night before replacing.

Old-Biscuit wrote:

RayChez wrote:

Rwake901 wrote:
I thought mine was bad too. Read your instructions, according to the instructions a small drip is normal. At least that's what mine say..

They should not leak at all. Nothing normal about having a water leak which would work its way into the sub floor and eventually cause some serious damage.

Normal/not normal.........

More like not uncommon for them to weep.
It is a very small closed system so pressures from swelling of water can cause them to weep and when they do it is outside of rig onto the metal pan. So sub-floor damage is not the usual issue.
Gas solenoid getting wet and then corroding is an issue with Suburban and with Atwood they can weep on the thermal cut-out and/or t-stat terminals corroding them.

So YES they shouldn't leak......but they occasionally do due to loss of air pocket and/or build up of deposits

For eleven years the pressure valve did not leak a drop of water on the water heater on my coach. Then I did not use the coach for about four months and when I fired it up again I noticed that the pressure relief valve was dripping. So I tapped it on the end of the valve stem and it stopped for another month or so. So on my next trip to Pahrump, Nev. while at the RV park I noticed it was leaking again. I figured, well it is just some sediment under the valve, so I figured by tapping it that it would stop. Not this time and it was wetting some electrical components. So I figured that was not good, so I decided to change it out if I could find the part. I checked to see what pressure the valve had to be and I found one at Home Depot. It took me about 15 minutes to change it out. The pressure valve was not even expensive if I recall.

So it is my theory that when those valves leak it is one of two things that has gone bad. Either your water heater is not cutting off when it reaches a certain temperature and it is blowing through the relief valve or the valve spring has lost its tension that it is suppose to have to retain certain pressures.

And yes it does have a little pan and a drain further down, but they are not suppose to leak if the water heater is working properly.

RayChez wrote:

Rwake901 wrote:
I thought mine was bad too. Read your instructions, according to the instructions a small drip is normal. At least that's what mine say..

They should not leak at all. Nothing normal about having a water leak which would work its way into the sub floor and eventually cause some serious damage.

Normal/not normal.........

More like not uncommon for them to weep.
It is a very small closed system so pressures from swelling of water can cause them to weep and when they do it is outside of rig onto the metal pan. So sub-floor damage is not the usual issue.
Gas solenoid getting wet and then corroding is an issue with Suburban and with Atwood they can weep on the thermal cut-out and/or t-stat terminals corroding them.

So YES they shouldn't leak......but they occasionally do due to loss of air pocket and/or build up of deposits

Thanks everyone! I'll try working the valve a bit under pressure and see if it stops dripping. Got another trip this coming weekend, so it'll be a good test to see if I got it right.

Rwake901 wrote:
I thought mine was bad too. Read your instructions, according to the instructions a small drip is normal. At least that's what mine say..

They should not leak at all. Nothing normal about having a water leak which would work its way into the sub floor and eventually cause some serious damage.