I am using a taco valve model 555-050RP. I have 4 zones to my boiler. The 3rd zone does not activate the boiler. When I checked the voltage across 1 and 2, I get 23.3 volts when the thermostat is turned up of course. I have jumpered the thermostat but I am not getting 25 volts to the taco valve...

Can we have a thread for these please? If you look close you can see the wet cardboard gasket between the rubber and sink. Nice

I replaced my DELETE control with a DELETE. Here is how the old wires were. C: white wire. R: red wire. Heat: blue wire. Heat: black wire. The DELETE has an extra slot labeled "t", but I don't have a fifth wire. Is there something I need to jump?