white rodgers zone valves

mburg

I have a customer with three white Rodgers zone valves, first floor, second floor, and indirect hot water heater. The first floor valve would not shut down a previous contractor replaced that valve, that did not fix the issue than they changed the thermostat that did not fix the issue either. currently I am at a bit of a loss as to what the issue is. I was thinking possibly the thermostat wire could have a short in it but when I was at the house all was working fine so I couldn't test that. the customer says when the valve wont shut down they turn the wheel and this keeps the boiler off until the next time the thermostat calls for heat. Which doesn't back up my thought of a short in the thermostat wire since the valve would just reopen. I was also wondering if possibly the transformer wasn't strong enough to turn the valve but it worked fine for 20 years. any thoughts would be appreciated.

icesailor

White Rogers zone valves are notorious for leaking around the stem and causing the contacts on the operating switch wheel to not make. It depends on whether it is a 2 wire or 3 wire valve. It is a simple swap out and you need to replace the internal part of the valve.

They either fail where they don't open with the thermostat and will if you move the wheel, or they open and won't close until you operate the valve.

You can sometimes spray it with electrical contact cleaner and get it to operate. Once it starts leaking past the shaft, it will only get worse.

http://www.emersonclimate.com/Documents/White-Rodgers/Catalog_2010/2010_Cat_pg_103.pdf

mburg

It's the 2 wire valve, and the valve has already been replaced so that rules out that issue.

icesailor

If it is a 2 wire valve, as I remember, the thermostat powers the valve open. When the power is taken off the valve, a spring closes it. Those were very popular in the 1960's, before the Taco 57* series wax motor valves. The 3 wire takes a 3 wire thermostat. One wire opens the valve. The other closes it. The stab wire connectors on the head were always a source of bad connections.

For some of us, the hair on the back of our necks gets hot when we go on a no heat call and see a W/R zone valve. We know that we will be on out toes.

mburg

The white Rodgers valves definitely make me confused

Empire_2

CHeck the end switch circuit on the zone valve. Your short may be there. follow the 2 wire cable ( in=f that's what it is) to the boiler. disconnect one side and see of the boiler shuts down. Since the boiler will not shut down, do this while it is running.


Mike T.

bob_46

does it have the push in terminals or screw or wire nut ?

icesailor

mburg said:

The white Rodgers valves definitely make me confused

Treat yourself right.

If YOU don't, no one else will.

http://www.taco-hvac.com/www.epa.gov/zone_and_flow_control_valves/zone_sentry_zone_valve/index.html

Idiot proof. Even a bad Sparky can't screw one of these up.

Califfi might make one too. I'm just not familiar with all their lines.

mburg

Two of the valves have push in terminals, the valve we are having issues with was just replaced with the screw terminals

mburg

Would having a short in the end switch in the valve prevent the valve from closing?

icesailor

Its been a long time.
I think that when the thermostat closes, it powers the valve open. The valve contact is a "warp switch". It holds the vale open. When the thermostat closes, the warps which opens and it powers the valve closed. \

If you read this PDF, you will know more than you ever wanted to know about them or how they work.

The Taco Zone Sentry valves are 100 generations of improvements.

http://www.emersonclimate.com/Documents/White-Rodgers/instruction_sheets/0037-5422.pdf

mburg

Thanks for the help!