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2oldman

south

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Posted: 01/12/21 10:59am Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

. I have NEVER in 41 years as an RV Tech had a specific complaint that the OP posted
and now you have 2.

Boon Docker

Mountain Foothills of Southern Alberta

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Posted: 01/12/21 11:05am Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

I am always amazed about perceived repairs to a simple problem.
1. I have NEVER in 41 years as an RV Tech had a specific complaint that the OP posted
2. WITHOUT the air gap in the Water heater, the pop off valve will leak once the HOT water in the tank reaches 150 psi. Without a INLET cold water Check Valve that pressure will extend to the cold water piping.
3. An accumulator tank is not needed for this specific problem. It may diminish the problem but you need to FIX the cause of the problem
4. Establish the Air Gap in the Water Heater Tank
5. Install a check valve on the Water Heater Cold Inlet. Doug

To restore the Air Gap
Turn off water heater.
Turn off incoming water supply.
Open the closest hot water faucet in the coach.
Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
Allow pressure-temperature relief valve to snap shut, close the faucet then turn on the water supply.


X2

time2roll

Southern California

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Posted: 01/12/21 11:17am Link  |  Quote  |  Print  |  Notify Moderator

2oldman wrote:

dougrainer wrote:

. I have NEVER in 41 years as an RV Tech had a specific complaint that the OP posted
and now you have 2.
Best to keep an open mind and learn something new.

IMO the disappearing air bubble in the water heater is a poor design.
I recommend the small ShurFlo accumulator for ALL RVs.


2001 F150 SuperCrew
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mobeewan

Hampton, Va

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Posted: 01/12/21 01:49pm Link  |  Quote  |  Print  |  Notify Moderator

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes. This is to counter the expansion of heated water in the WH and hot water lines and prevent unnecessary cycling of the WH relief valves. So as mentioned introducing air into an RV WH or adding an accumulator tank in the hot water line should solve the problem unless there is a problem with the WH itself over heating the water and or the relief valve has failed to operate.

Although someone mentioned adding air by using a drained water hose on the city water connection, if you blow out your water lines to winterize, a shot of compressed air into the city water connection with a hot water faucet open will add air to the WH to reestablish the air pocket.

Lynnmor

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Posted: 01/12/21 03:13pm Link  |  Quote  |  Print  |  Notify Moderator

mobeewan wrote:

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes.


I believe that is local codes, it wouldn't make sense for those on a well with an open system that has no check valve after the tank.





time2roll

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Posted: 01/12/21 03:23pm Link  |  Quote  |  Print  |  Notify Moderator

mobeewan wrote:

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes. This is to counter the expansion of heated water in the WH and hot water lines and prevent unnecessary cycling of the WH relief valves.
Yes especially in hill country where city pressure is 150+ and the home will have a pressure reducing regulator that effectively creates a closed system. The days of the city maintaining 50 psi and the meter flows both ways does not apply to everything anymore.

My local water company required a backflow device a couple decades ago. I started having slab leaks until the accumulators were installed. 2x 100 gallon water heaters with no air pocket can expand quite a bit.

The RV water inlet has a check valve that creates the same closed system conditions.

Gdetrailer

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Posted: 01/12/21 03:35pm Link  |  Quote  |  Print  |  Notify Moderator

Lynnmor wrote:

mobeewan wrote:

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes.


I believe that is local codes, it wouldn't make sense for those on a well with an open system that has no check valve after the tank.


A "properly" installed water well WILL have a check valve at the pump.

Never want water to flow back into your well.

My well driller put a check valve above the submersible pump down the well.. I have an additional check valve between the pressure tank and well head for good measure.

No check valve at my water heater and never had issues with T&P valve seeping or leaking on my home system.

The OPs issue, I think folks may be overlooking is they may have a FAULTY TOILET valve..

I ran into that with a brand new toilet I bought to replace the 1980s toilet in my TT. The original 1980s toilet I fought constant leakages since I had bought it.. Replaced the water valve hoping that would fix the leaks.. Nope, turned out the toilet had cracks in the plastic all over the place..

Figured the new toilet would fix my leaks.. NOPE. Didn't leak when I was hooked up to my home water system which is set to a max of 50 PSI..

Hooked up to a campground and had leaks at the toilet again!

Fought that for several yrs..

Finally got fed up with these leaks, and one night at a campground I watched the connections at the toilet valve very slowly leak a little drop of water every half hr..

Bought a replacement valve and no more leaks..

The original valve had a slight weld mismatch in the plastic right near the inlet.. Came that way right from the manufacturer [emoticon]

The mismatch in the plastic weld of the flush valve was OK with LOWER pressure on my home water system, but it would weep when hooked up to a campground which had considerably higher water pressure than my home system.

My suggestion is the OP needs to gain access to the water flush valve and monitor where the water leak is really coming from..

Not sure what toilet the OP has but my replacement was a Thetford bravura..

Lynnmor

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Posted: 01/13/21 05:32am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:

Lynnmor wrote:

mobeewan wrote:

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes.


I believe that is local codes, it wouldn't make sense for those on a well with an open system that has no check valve after the tank.


A "properly" installed water well WILL have a check valve at the pump.

Never want water to flow back into your well.

My well driller put a check valve above the submersible pump down the well.. I have an additional check valve between the pressure tank and well head for good measure.



Correct, the check valve(s) is on the PUMP side of the tank, not on the HOUSE side. The tank has the air pocket to keep pressures from going too high. What I said before is correct.

Gdetrailer

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Posted: 01/13/21 08:57am Link  |  Quote  |  Print  |  Notify Moderator

Lynnmor wrote:

Gdetrailer wrote:

Lynnmor wrote:

mobeewan wrote:

Accumulator tanks are now required at the hot water outlet pipe of water heaters on residential construction and when replacing WHs in existing homes.


I believe that is local codes, it wouldn't make sense for those on a well with an open system that has no check valve after the tank.


A "properly" installed water well WILL have a check valve at the pump.

Never want water to flow back into your well.

My well driller put a check valve above the submersible pump down the well.. I have an additional check valve between the pressure tank and well head for good measure.



Correct, the check valve(s) is on the PUMP side of the tank, not on the HOUSE side. The tank has the air pocket to keep pressures from going too high. What I said before is correct.


I was giving a bit more complete explanation on a HOME well system which lead into the fact that the OPs TOILET VALVE actually may be at fault similar to what I ran into.

Something else also, unless the water heater is heating the water to high enough temps to create steam I highly doubt that it will cause enough pressure without an air pocket to cause the toilet to start leaking unless there is a FAULT at the toilet..

The T&P valve IS there to relieve WATER PRESSURE in the event of over water heater overheating..

From HERE

In a standard water heater, the water is heated by a gas burner or electric elements. As the water reaches temperatures between 120 and 140 degrees Fahrenheit, both the water and the water heater's metal tank expand. Some expansion is normal, but too much expansion is unsafe. When the temperature reaches 210 degrees or the pressure reaches 150 psi (pounds per square inch), a properly functioning T & P valve opens and expels hot water and steam through the discharge tube.

One would really need to put a pressure gauge on the system and monitor the pressure to see what is really happening rather than making a bunch of guesses..

OP could even have a faulty pressure switch on the water pump but in reality the toilet should not leak even with CITY water pressures up to 100 PSI or better (yes, city water CAN get there).

Under NORMAL conditions with RV water heaters I have seen T&P valves "weep" some even with a newly filled water heater tank. And that may be partly due to a small air pocket but also have to consider RV water heaters operate at a much higher temp, of 135F to even 140F..

As far as the check valve goes on the inlet of the water heater, it should have had one from factory, even my 1980s TT HAS ONE.. Of course, with the factory check valves they use the cheapest ones they can get their hands on which are typically the plastic body with inline spring and plunger and the plunger has a rubber gasket that fails.. I changed mine to a all brass swing check valve for more reliability and much quieter operation (that plastic valve would "sing" when water was moving and DW didn't like the noise).

And yes, I would agree that some expansion tank may be nice to have as it will buffer the water pump but it is most likely not the fix or issue here.. I suspect the issue IS the OPs toilet water valve..

Old-Biscuit

Verde Valley

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Posted: 01/13/21 10:05pm Link  |  Quote  |  Print  |  Notify Moderator

T&P on RV water heater will weep at 125 psi


Not many RV MFGs install a check valve on INLET
And not many have issues with T&P weeping but it does occur
Some can experience weeping EVEN with an air pocket....that is where an accumulator tank can help
** most install accumulator tanks to help with pump cycling during low demand & being able to turn pump off at night and still be able to flush the toilet
But they will also help control system pressures

My WH Tank does NOT have ANY check valves..has 3 shutoff valves
And even w/o check valves I have never had T&P weep except when air pocket was lost.


Is it time for your medication or mine?


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