Hot water coming through cold lines

04FV270riverrat

hot water coming through cold lines

aero3113

Strange that you have “T’s” with the cross over line. Maybe the valve on the cold line needs to be turned?

Stodge

Yeah that cross over from hot to cold seems odd.

raybo3

Those 2 Tee's makes no sense. I think they may have been added for winterizing but they should not be there........

04FV270riverrat

Would I need a pex adapter to NPT to take the T's out or would those fittings screw right on to the brass fittings?

Handymans342

Thats a hot water bypass for winterizing. I would say the valve is not working 

Handymans342

Try pointing it towards the heater

Liberty44140

Yea I’ve got the same set up as the pic but I don’t remember the valve shown on the cold side, wonder if it’s broken or should be open. 

04FV270riverrat

Liberty44140 said:

Yea I’ve got the same set up as the pic but I don’t remember the valve shown on the cold side, wonder if it’s broken or should be open. 

the valve either directs the water into the tank (current position) or you can turn it to 90 the flow toward the left (in pic) toward the red line.

04FV270riverrat

Maybe I need another valve on the hot water side like below....

04FV270riverrat

I guess I could just take the T's out and pipe them directly to the heater with these

Willhound

That's what's on mine. I just pull them off the hot water tank and join them with a nipple to run pink anti freeze thru the lines when winterizing. 

GMSLITHO

no tee on mine just direct to the heater cold in and hot out  and I disconnect when I  winterize 

reneechris14

@Handymans342 is right point the t to the heater.

reneechris14

2 tees  are the right way for winter.

Wildboating

That is different, no tees on mine and knock on wood, still no problems winterizing.

GMSLITHO

when I winterize I just drain the tank and clear it with a shop vac then just winterize the water lines 

04FV270riverrat

So I replaced the T setup with a straight in and straight out. I'm still getting hot water from the cold side of the faucets. Is there supposed to be a check valve on the inlet side of the tank? Maybe I'm missing that.

randy56

Are all faucets reversed? then reverse the line at the hot water heater.  

Handymans342

Yeah must be reversed under faucet

Handymans342

Or cold and hot reveresed at heater

04FV270riverrat

Ok so here's a new twist.

I double checked all my blue lines were hooked to blue and red to red under the wire looms running in the engine compartment. 

I added an inline check valve on the inlet blue line to the water heater. Once I turn the heater on and it gets warmed up I can feel heat on the blue inlet line between the check valve and the tank. My cold water in the boat is now just cold and the hot is just hot. All seems good.....until.....

Now as soon as I turn on the cold faucet, the pump comes on and short cycles until you open the faucet up to get a solid stream of water then it just runs constantly until you shut the water off. Is their a bladder in the water heater that keeps the pressure until it bleeds off? Before when I was getting hot from the cold, I could turn the pump on a build up pressure, then open a cold faucet and run it for a little bit until the pressure lowered and the pump came on, now the pump runs as soon as you open the faucet. It only does this on the cold side though, not with the hot water faucets.

Willhound

What you describe is pretty much how mine is.
Pump comes on as soon as cold side opened. Short cycles at low opening, constant run on higher opening. Slight lag on the hot side presumably from a bit of pressure in hot water tank. But no bladder in tank that I'm aware of. Just like any marine or RV water supply pump they run on demand.

04FV270riverrat

Willhound said:

What you describe is pretty much how mine is.
Pump comes on as soon as cold side opened. Short cycles at low opening, constant run on higher opening. Slight lag on the hot side presumably from a bit of pressure in hot water tank. But no bladder in tank that I'm aware of. Just like any marine or RV water supply pump they run on demand.

maybe mine used to not run as soon as the faucet was opened because the hot water from the tank was running back out into the cold lines. Oh well, its great now having a constant temperature in the shower!

Dude_Himself

Have you bled all the air out of the hot water tank? That's the only thing I can think of that would cause all your symptoms. As the water heats up, with an air pocket, it will boil and expand, providing back pressure into the supply line.