cancel
Showing results for 
Search instead for 
Did you mean: 

Hot water bypass

jeremywatco
Explorer
Explorer
Hi all,

Out beach camping and this morning had no hot water and water heater wouldn't turn on. After an hour of messing with it I realized what happened was someone must have bumped the hot water bypass as the water was plenty hot in the tank thus why the heater wasn't coming on.

Anyways the issue I'm having is that if I even crack the bypass towards bypass to temp the water down I get zero hot water. Also on my facuets with hot water working if I move to the slightest bit cold I get no hot water. So its kind of like burning hot or cold no warm.

Any ideas?
7 REPLIES 7

Old-Biscuit
Explorer III
Explorer III
Dusty R wrote:
There are check valves, both in and out on most water heaters, one of them is not allowing water into the water heater.


Some...not most
Some may have one on cold inlet
Some have on hot outlet (seems more common)
Some don't have any at all (3 shut-off valves instead)
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

Dusty_R
Explorer
Explorer
There are check valves, both in and out on most water heaters, one of them is not allowing water into the water heater.

Old-Biscuit
Explorer III
Explorer III
jeremywatco wrote:
Old-Biscuit wrote:
The bypass valve is NOT used to 'temp' the hot water down.
Cold inlet valve should be wide OPEN & bypass fully CLOSED when WH is in service.
With the bypass cracked open the cold water line is connected to hot water line and the hot out check valve is being closed from cold water pressure.
You control water temp by mixing cold/hot at the faucet.

With bypass closed and no hot water flow.........check valve on hot outlet stuck closed.

Turn off water supply, open WH PRV to relieve pressure in tank and let water drain down in from top of tank.
Disconnect Hot outlet line
Inside the fitting on tank is a cheapo plastic plunger/spring/o-ring valve. Held inplace with a clip. Remove clip and internals. Then connect water line.
Turn on water supply...heat water........voila Hot water flow.

Then at you convenience install a shut-off valve in hot outlet lne and forget about that stupid check valve.


Got it, this makes perfect sense.

Is it normal for me to have much lower hot water pressure than cold water using water pump or city water? I'd say about 50-75% the flow

Shouldn't be a noticeable difference in flow Hot vs Cold.....unless something in hot side is plugging/stuck.
And the only thing in hot side not in cold side is the check valve on WH hot outlet.
Have you looked at it?
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

jeremywatco
Explorer
Explorer
Old-Biscuit wrote:
The bypass valve is NOT used to 'temp' the hot water down.
Cold inlet valve should be wide OPEN & bypass fully CLOSED when WH is in service.
With the bypass cracked open the cold water line is connected to hot water line and the hot out check valve is being closed from cold water pressure.
You control water temp by mixing cold/hot at the faucet.

With bypass closed and no hot water flow.........check valve on hot outlet stuck closed.

Turn off water supply, open WH PRV to relieve pressure in tank and let water drain down in from top of tank.
Disconnect Hot outlet line
Inside the fitting on tank is a cheapo plastic plunger/spring/o-ring valve. Held inplace with a clip. Remove clip and internals. Then connect water line.
Turn on water supply...heat water........voila Hot water flow.

Then at you convenience install a shut-off valve in hot outlet lne and forget about that stupid check valve.


Got it, this makes perfect sense.

Is it normal for me to have much lower hot water pressure than cold water using water pump or city water? I'd say about 50-75% the flow

Old-Biscuit
Explorer III
Explorer III
The bypass valve is NOT used to 'temp' the hot water down.
Cold inlet valve should be wide OPEN & bypass fully CLOSED when WH is in service.
With the bypass cracked open the cold water line is connected to hot water line and the hot out check valve is being closed from cold water pressure.
You control water temp by mixing cold/hot at the faucet.

With bypass closed and no hot water flow.........check valve on hot outlet stuck closed.

Turn off water supply, open WH PRV to relieve pressure in tank and let water drain down in from top of tank.
Disconnect Hot outlet line
Inside the fitting on tank is a cheapo plastic plunger/spring/o-ring valve. Held inplace with a clip. Remove clip and internals. Then connect water line.
Turn on water supply...heat water........voila Hot water flow.

Then at you convenience install a shut-off valve in hot outlet lne and forget about that stupid check valve.
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

starsabove
Explorer
Explorer
I am pretty new here but I might know what it is. First do you have full flow coming out of you hot water facet if not you might not have your cold water inlet to your hot water heater open all the way thus with a slow fill your hot water heater will be always hot, and when you open your cold facet you overcome any hot coming out. make sure all valves are open full. good luck

rav
Explorer
Explorer
is it only one valve for the bypass our TT has 3 valves the MH has 1. also check the outside shower if you have one to make sure the valves are closed.