Zone gets hot when another zones calls for heat. Any Ideas?

pmanidis

I have a hot water system that has four zones. I have one zone that gets hot (even when shut off) whenever any other zone calls for heat. I have had the Taco valve replaced already. Any Ideas? This a new problem the system has worked for years without this happening.

RoosterBoy

it may depend on what you replaced the valve with...

i think you could check the valve and see if there is a metal handel locked in the open /manual position.

boiler man_2

check wireing

only 3 zone valves can operate on a 40 va transformer.If all 4 are on one 40 va. transformer that could be the problem.if not check the wireing just to make sure.Did you have the head changed and not the body? if you did not change the body it could be a piece of solder or scale stuck in the valve body.

james patrick

maybe?

I've had the same thing. It was a stuck open check valve on that zone.