check valve on water heater ?

[woodsmaster]

I noticed that hot water was back siphining when we would flush toilets etc. We have an old 2" well and pump, non bladder tank. So I put a check valve on the elec. water heater and it solved the problem and the elec. bill
droped $20.00 month. haven't had the pressure relief valve pop off yet and I installed the valve a few months ago. Question is should I have an expanshion tank ?

 

[rowerwet]

yes, just to be safe it would be a good idea. otherwise the cold water entering the heater and expanding could cause a rupture somewhere.

 

[webie]

yes, just to be safe it would be a good idea. otherwise the cold water entering the heater and expanding could cause a rupture somewhere.

I am not so sure I would do this , my reasoning is is he does have the safety pop off if the expansion is to great the second is If he added an expansion tank that would negate the safety pop off in case the water heater would over heat there by not allowing cold water to cool the heater .
My AO Smith gas water heater actually is factory equiped with a check valve in it to elimanate thermo siphoning .
Just my opinion here .
Webie

 

[LLigetfa]

One should never rely on a pressure relief valve. It is like an air bag... good to have but hope it never goes off. If the home doesn't already have hammer stops, install the largest stops you can find at the ends of the runs. They will provide some expansion relief.

 

[rowerwet]

and like an airbag the temp/press valve won't always work the same afterwards and it can make a big mess when it works as required, most people don't have a good system set up to drain away from the temp valve and if it gets a little junk under the seal it will drip and need to be changed.

 

[LLigetfa]

When I was changing out my old water heater, I tried tripping the pressure relief valve and it was seized.

 

[woodsmaster]

I think I'll go with the water hammer idea. When my washer quits drawing water I hear the pipe hammer, maybe I can kill 2 birds with one stone.

 

[Highbeam]

They make little heat trap devices that thread onto the inlets and outlets of the water heater. Is that what you're talking about? They didn't seem quite as substantial as real check valves but maybe they are inside. I would very much recommend (and current codes require) a standard sized expansion tank on the hot water system.

 

[webie]

They make little heat trap devices that thread onto the inlets and outlets of the water heater. Is that what you're talking about? They didn't seem quite as substantial as real check valves but maybe they are inside. I would very much recommend (and current codes require) a standard sized expansion tank on the hot water system.

Current codes reguire a expansion tank On a DHW ? Never ever heard or seen such a thing before .

 

[semipro]

They make little heat trap devices that thread onto the inlets and outlets of the water heater. Is that what you're talking about? They didn't seem quite as substantial as real check valves but maybe they are inside. I would very much recommend (and current codes require) a standard sized expansion tank on the hot water system.

Current codes reguire a expansion tank On a DHW ? Never ever heard or seen such a thing before .

This became necessary when check valves were installed on water lines entering houses from municipal systems. These valves prevent possibly contaminated water from entering the municipal distribution system when system pressures drop. An expansion tank is not necessarily needed on a well-supplied system.

 

[Highbeam]

In my city the water meter setters include a check valve as semipro describes. When we replace services we often "create" a leaky water heater this way. I am fairly certain that code requires the normally blue tank that's about 2 gallons in size for new construction. If you are on a well system then the big blue 80 gallon expansion tank(s) will do the job unless you add a check valve at the water heater.

 

[woodsmaster]

I need to install a new pressure gauge on my holding tank. Don't think my pressure is very high to begin with and probably why I haven't had any problems with expansion yet. Think I will install expansion tank,
water hammers, and maybe even a new bladder type tank and gauge while im at it.