Weil Mclain CGi boiler, honeywell zone valve

Horseman

My gas fired CGi boiler is showing LED codes and not working. It started out occasionally doing it. I would shut off power, turn back on, and it would work again for a day or so. After checking thermostats and wiring etc, it started again and ran for a couple days but isn't working again now.
- 2 zones - garage - basement
- the garage tstat will trigger the zone valve and the boiler will try to run but then flashes the tstat/circ LED
- the basement tstat will do nothing (couple days ago it would turn on the boiler fine)

I have jumpered the tstat wires from the boiler control box and the boiler will start and run fine.
I have tried jumpering the tstat wires on the basement tstat and it does nothing.

Could the basement zone valve motor be bad? Could this one zone valve malfunction also lead to the garage tstat and zone valve to still work but not actually turn on the boiler properly and make it error code?

I plan on testing each tstat wire connection back from the boiler and see if the 24 volts is present at each connection. I have checked all the connections visually to make sure they were all still connected.(even scraped all the wires slightly at each connection to confirm good contact.

Will manually opening the zone valve tell me anything about whether the zone valve motor is bad or if it is a wiring issue.

icesailor

If you jump the TT connections on the main burner control, and the burner doesn't start, it is likely that the problem isn't in the zone valves.

What kind of ignition does it have? Standing pilot, hot surface igniter or spark?

If the burner should start when you jump the control, do NOT let it keep running. You need professional help.

Horseman

I have jumped the TT connections and the boiler will light and run fine. So the problem should not be the control panel.
It does not have a standing pilot light. It has a self igniter.
I think it is an issue with the wires running from the thermostats to the zone valves , or with the zone valve itself.

I have tried cleaning the thermostats, tried jumping thermostat wires, cleaned pressure switch hoses, checked the flue for obstructions, checked water pressure.

The only thing I can find out of order is the basement zone valve not opening when the thermostat is turned on. (occasionally it works) So I figure it is causing the control box to see an issue and continually shut down and flash LEDs. If the motor on the valve is broke, could it make resistance in the wires to make the boiler fail even if that zone isn't turned on asking for heat?

icesailor

You need a Multi-Meter and an Amp Champ. Or someone that has them and knows how to use them.

You're going to go to low voltage electrical college.

Tim McElwain

What were the LED codes, that is important and you have to start there.

Horseman

The green power light is on steady the tstat/circ light is flashing. The limit light is on steady. According to the manual the tstat light flashing means a stray voltage in te thermostat wires.
When the light flashes the voltage in the tstat wires at the boiler fluctuated from 16-18.4 volts.
I am going to label and undo all the wires and make my way through each connection and try hooking up different zone valve to see if it is a bad zone valve or poor wiring.

Horseman

So after switching the zone valve motors, the one I suspected was bad didn't work on the other thermostat line and the one that was working did work in the other position. So I am buying a new zone valve.

My new question is, when I tried just disconnecting one of the zone valves altogether the boiler would still show the tstat-circ LED and not work? If I hooked up the bad zone valve and manually pushed in the end limit switch on the zone motor the boiler would run fine.

From the boilers TT wires it goes to a red and black 2 wire thermostat wire up to a transformer looking box. From there the red and black wires are connected to a new 4 strand wire, 2 of those wires(white and green)are attached to the transformer. The other 2 wires (red and black) are connected to the wires coming from the boiler. Is that transformer looking thing used because I have more then one zone? And then if one zone motor is bad or if I remove one zone it tells the boiler there is a problem?

The transformer box thing I am talking about always has 26 volts when power it turned on.

SWEI

Is there more than one 24 VAC transformer in the system? Disconnect the one you can see and look for voltage on any wire anywhere -- sometimes they are hiding in attics and even inside walls.

Horseman

There is only the one 24v transformer, but there is also 24 volts coming out of the boiler control panel itself. So I think because there is 2 power sources that when I disconnect one zone valve or the zone motor is faulty there are too many volts running through and causes the LEDs to flash.

SWEI

Two transformers, one inside the boiler -- very common setup. Check your wiring carefully -- can you post a schematic?

Horseman

Horseman

I was able to find a new motor for the suspected faulty zone valve(basement zone). I replaced it and now the zone motor activates properly when the thermostat calls for heat and the boiler runs.
However once the thermostat is satisfied and the motor releases and the end switch is released then the boiler won't run and throws the tstat code again. I now suspect the end switch is bad on the that same valve. If I manually push in the end switch or if I turn up the tstat again and the motor activates and pushes in the end switch it will run fine.
The garage zone valve can open and close as the thermostat wants and the boiler will continue to run fine as long as the basement zone valve is pushing the end switch or if I manually push in the end switch.

While the boiler is running (end switch pushed in) there is no voltage in the red and black tstat wires anywhere down the line. Once the end switch is released on the basement valve, there is a voltage from 16 -18volts on the tstat wires.

I am now shopping for a new end switch or a complete new head for the zone valve. Can a bad end switch cause this sort of problem?