Accumulator tank for water heater

[DestinationStation]

Occasionally I have a water alarm go off behind the nautilus panel. Only happens every so often when the water heater is on, pressure builds (not enough to exit through the T & P valve) and I get a small leak. I've read in this forum about people adding an accumulator tank after the water pump to get rid of the pulsating water when using the pump. I can't find any info on people adding a accumulator tank to absorb the extra pressure when the water heater is on. Any advice is appreciated... Will it solve my problem and where do I put it? Thanks in advance.

I'm aware of the air pocket in the water heater that's supposed to prevent this issue.... over time it goes away. So my question is for those that have input about adding an accumulator tank for the increased pressure when my water heater is turned on. T & P valve works fine.

[LanerC]

I think you would put a very small expansion tank on the cold water side of the hot water tank, right above the hot water tank, before the check valve. Not sure if there is room though. Or try a lower pressure, pressure regulator on the hydrant supplying water to your camper. Of course make sure all of the connections behind the Nautilus panel are tight. Happy camping!

[Najataagihe]

Actually, you can put an accumulator tank anywhere it can fit.

It doesn’t have to be above the tank or any other particular location, nor does it have to be any particular shape.

Tall and skinny works just as well as short and fat.


For smoothing out water pump pulses, >25 cu in of volume, spliced in some where in the cold supply, after the pump and before the rest of the plumbing, will work marvelously.

For hot water expansion, you should only need >10, spliced between heater and valve (if any) on the hot supply.


The only requirement is that the connection on the tank be on the bottom of the tank.


If you want to build your own, it’s quite simple, but remember to use CPVC pipe on the hot side, not plain PVC.

Take a length of CPVC or PVC and two matching end caps.

Drill a hole in the center of one of the end caps and insert a “T” fitting.

Instant (after the solvent dries) accumulator tank.


I’ve used every size from 1/2” to 6” diameter pipe.

1/2” is more for eliminating water hammer at the faucets or heater expansion.

My favorite size accumulators were built from 3” or 4” diameter pipe.


I found out that one I built in 1988 worked right up until they dismantled the installation, last year!

Thing cost less than $10 for the cement, two end caps and the “T”.

The pipe was scrap we had lying around.


Don’t worry about the air in the tank.

It will replenish when you drain the system for winterizing.

[huntindog]

Occasionally I have a water alarm go off behind the nautilus panel. Only happens every so often when the water heater is on, pressure builds (not enough to exit through the T & P valve) and I get a small leak. I've read in this forum about people adding an accumulator tank after the water pump to get rid of the pulsating water when using the pump. I can't find any info on people adding a accumulator tank to absorb the extra pressure when the water heater is on. Any advice is appreciated... Will it solve my problem and where do I put it? Thanks in advance.

I'm aware of the air pocket in the water heater that's supposed to prevent this issue.... over time it goes away. So my question is for those that have input about adding an accumulator tank for the increased pressure when my water heater is turned on. T & P valve works fine.

i would fix the leak first.

[traveldawg]

i would fix the leak first.

I agree with huntingdog.

[Kevin2282]

i would fix the leak first.

Yes, fix the leaks first. My 28BH had a massive amount of leaks and I ended up re-plumbing most of it with PEX. Search my user name for the 28BH writeup. One thing most RV owner don't realize is that when the water heater turns on there is a massive pressure spike that gets put on the water system. This pressure spike can get well over 100psi. Any weak spot or loose fitting will leak. I put a inline pressure gauge and a 80 psi pressure relief valve on my system. On a recent trip the campground water pressure was a constant 40psi and my water system would peg at 80psi every time the water heater activated. At that point the pressure relief valve would open and slowly bleed off pressure to keep it from going over 80psi. I ran the bleed off line out the same opening as the low point drains.

Pex Drop Ear Fitting
https://www.amazon.com/EFIELD-Female...NrPXRydWU&th=1

Adjustable Pressure Relief Valve
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Installed Photo in my 28BH



Added Edit: Before I had a chance to change the plumbing to PEX and install a permanent pressure relief valve, I attached the pressure relief valve to the hot side low point drain before each trip. This worked great to keep the pressures from spiking.