In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Greetings fellow Wallies. As a service tech in the Chicago area, forced air outnumbers hydronics by a wide margin and radiant floors are still few and far between. I've just seen my first Wirsbo radiant system with Wirsbo controls. Much of it makes sense but there's a lot still unfamiliar. I'd appreciate help from anybody more familiar with these.
Each zone is controlled by a t87 thermostat with "Wirsbo" where "Honeywell" should be. There's no adjustable anticipator. 3 wires go to R,W and Y on the subbase. The customer had a 200+ page book showing dozens of wiring diagrams but I wasn't able to find one that matches exactly what I was looking at. One diagram showed the third wire going to transformer C and doing something with an anticipator. As I recall, I was getting voltage across R-Y regardless of call for heat so it's not set up as a call to close a WR 3-wire zone valve screw #6.
The thermostat connects to a printed circuit board(zone control module, ZCM) capable of serving 3 zones. Each zone has a yellow indicator light showing a call for heat and a red light showing a closed zone valve end switch. The ZCM has 2 screws on the left for R & C and 2 screws on the right, a pair of contacts to complete a separate control circuit to go turn on the circulator.
The zone valves mount to the top of the return manifold. The PEX tubing mounts below each zone valve. Tubing is about 7/8 od so id is 3/4 or 5/8. Yellow yellow is call to open. Red red is end switch. Some of the valves have beige plastic covers and the number A302XX0261. Others have metal covers with one slot and an indicator that is centered over a dot when it is tightened sufficiently. The metal ones have another slot with a pointer indicating open.
One of the 8 zones has too much heat and one has not enough. The problem zones are two small bedrooms with the beige valves. I suggested that the thermostats may be wired to each others' rooms. The customer says her engineer husband has spent a lot of time turning the thermostats up and down and would have probably noticed if that were the case.
More background: House built approx 1996. System is of similar vintage. Reset talks to motorized mixing valve. Customer moved in this past summer. Previous owner says some of the zone valves had been replaced. I don't know if the metal or plastic ones are original.
Okay, here's my question. Can these zone valves malfunction in such a way so that the indicator lights turn on and off in the correct sequence but the valve is stuck?I'd also appreciate any troubleshooting hints on these. You can't go into the room and grab a pipe then go to the manifold and feel the hot return.
Service Technician Extraordinaire (trying hard)