Very Old Stuff

Yvonne Burch

Hi Dan, It's been a while. I have run across an old hydronic ceiling system. It is in a 12 story building and I have hot water to the very old, what I would call a zone valve, but the info on the actual head is "Electric Radiator Valve". I actually was able to find a readable part number too. It is a Honeywell V2008A30R5X1. It has been torn apart. I managed to figure out how to put it all back together again. It is running off of two 24 volt 40 va transformers, which are both working now. One transformer goes directly to the actuator and the other goes thru a newly installed thermostat, not by me. There are three wires, red white and blue, on the actuator that tie in to the t-stat. It used to go thru a very old thermostat part number TA247A1C87X1 Honeywell again. The problem is that the valve will not open when the thermostat calls for heat. I can take an Allan wrench and "jump start" it. The actuator will go fully open and then close again, and I am getting plenty of hot water thru when it is open. I need some information at to how this valve works so I can determine if the new thermostat is the problem. Do I need a single throw double pole t-stat. Or even some info on the old t-stat to tell me how it operates. Of course there is no wiring schematic on either of the VERY OLD parts and I called my most knowledgeable whole saler to look up info for me and he could not find any cross-reference from the old numbers. But he was able to give me a new set up that would work for the system.
I believe that the new t-stat either wired in wrong or is not the correct style. It is a basic heating and a/c t-stat. It is wired to the rh, w, and yellow terminals now. It just doesn't make sense to me with out a road map (schematic). Help!!!!

c-rex

this sounds like

a seris 10 t-stat is needed. years ago a holding coil was used on a heat call to keep the valve open. a three wire t-stat ought to work, good luck.