Water Heater Check Valve

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Allezcat
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Water Heater Check Valve

Post by Allezcat »

Problem; No hot water flow. The water just drips out of the faucets and eventually gets hot.

Fix; After draining 6 gallons of water (waited until it cooled), I found a brass check valve at the cold water inlet to the tank. Inspecting it, I found it stuck closed, blocking the flow. After manually opening and closing it, it seemed to free up some, but I was not confident it would operate normally when back in the system. I removed the valve portion and replaced the fitting which now gives full flow to the hot water system.

Question; Will this cause any problems, having removed the check valve portion? I can't see how hot water would ever flow back into the cold.
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SecondWind
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Re: Water Heater Check Valve

Post by SecondWind »

Chet,

The water will expand as it heats and may flow back into the PEX piping, causing the pressure to rise. It could burst the PEX if the pressure gets high enough.
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duetto
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Re: Water Heater Check Valve

Post by duetto »

is it the original water heater? if so what make model is it?
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Allezcat
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Re: Water Heater Check Valve

Post by Allezcat »

I believe the water heater is original. It is a Force 10 Model 40603. The brass check valve threads into a SS elbow which is threaded into the inlet of the tank. The blue PEX slips on the inlet side of the brass check valve. I would guess the check valve is a PDQ part?

Chet
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Re: Water Heater Check Valve

Post by duetto »

hi chet,

we replaced our force 10 years ago, so i maybe rusty on some details. as i recall it has a std hot water heater pressure relief valve. if so, i think the only possibility is to keep hot water in the tank. as far as pex is concerned i don't know if the red & blue have different temp range. if they're the same then i don't think it matters.
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Captnautigal
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Re: Water Heater Check Valve

Post by Captnautigal »

Have to tell you we replaced our water heater at Stuart Yacht while hauled out with our shaft issues. I was tired of waiting for hot water when showering. Refused to stand under cold water - so always wasted the first few gallons waiting for it to arrive from the aft port hull. We bought a new Isotemp 6 gallon w/h - no longer use the heat exchanger option (but its there). Mounted it in the forward hull in front of shower over round hatch access. Stuart Yacht made special brackets to hold the water heater up and still be able to get at round hatch cover in floor. Advantages of Isotemp - 750 watt element allows a/c in salon and hot water heater to run at same time. Still get hot water while running boat since we passed it through the invertor. Excellent insulation holds hot water at temp for at least 12 hours!!!! - GREAT ACCESS BEHIND PORT ENGINE - espescially if we have to clean the a/c strainer or get at plumbing for transom shower. Best of all not more that four seconds and hot water at shower head!!!
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Re: Water Heater Check Valve

Post by duetto »

hi dave,

we too switched to the 750W isotemp but it's still in port hull. had we continued to do icw i was going to add one of those electric instant water heaters right in front of shower to eliminate the wait for pipes to heat. had i done that we would've had to run genset but would have been a small price to pay for hot water.
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Mary & Roger
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Re: Water Heater Check Valve

Post by Mary & Roger »

If you can extend the hot water pipe from the heater with copper about 10" then connect the pex, that will keep the pex from having any problems. That is a plumbing code in NC. Lowes or Home Depot cary them ready made, eather flex or bent. Roger C.
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Re: Water Heater Check Valve

Post by Allezcat »

Thanks Roger
There is an 18" flex line from the hot (outlet) of the tank to the PEX fitting. Should I do the same on the inlet? As it is now, the blue pex fits directly into the cold (inlet) of the tank. I checked the temp./pressure rating on the PEX. It is 180F@100PSI.
Chet
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Re: Water Heater Check Valve

Post by Mary & Roger »

Hi Chet, you don't need long copper on the cold side. Roger
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