I had a chance to test it with a multimeter. When I use continuity test I get no beep... But when I use resistance test it starts with negative and goes up to almost 2k positive (sorry if it sounds dumb but as I said it's new to me). Does it mean it's faulty?...
New thermostat, old problem (wiring issue?)
- Thread starter Karolisko
- Start date
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Just to be clear, is this checking for continuity on the detached T4?
With the probes in A and B, there should be no continuity when the thermostat is not calling for heat.
There should be continuity between A and B, when the thermostat is calling for heat.
The resistance measurements you give, sound as if you were checking for continuity on the cables from the boiler - if the boiler was off (and I hope it was), a small voltage from the boiler would create measurements like that (possibly from a capacitor discharging from the boilers circuitry).
Ensure batteries inserted in the T4, remove the two wires if installed and select a high setpoint temperature say 30C, yyou should hear a click and you will probably see a little flame signal illuminated in the display, put the M.meter to resistance and touch the 2 probes together. it should read 0, (M.meter check) then place one probe in A and the other in B, youe should get 0 which means the stat is OK, if you wish reduce the temperature setpoint down to say 10c, you should hear the contacts opening and the m. meter reading will look like a 1.
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OK, so it's definitely wrong. Not sure how I got the varying reading yesteday but today it stays at 1 when testing for resistance and no beep when testing for continuity.. And yes, I did all the test on a disconnected (but battery powered) unit.
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Just to clarify - the unit was calling for heat (requested temperature being higher than room temperature)
You are testing the remote temperature sensor connections (SS), which would explain your resistance readings.
The A,B,C connections are the three terminals above.
As in the reading stays at 1.
Within the thermostat unit itself? Yes. It clicks but there is no difference in reading (at least how I do it) before and after (no heat demand / heat demand)
Multimeter reading i meant
On reflection, you may have to have the whole T4 unit assembled (with batteries). So remove it and connect two bits of wire to terminals A & B, reassemble it, turn up the heat setting to get the flame signal on and test for continuity (o) with the M.meter connected between the two wires, turn the setting down to check that the contacts open, M.meter reading 1.
Why are you probing the bottom two terminals??, if you look at my post #12 it looks like A & B are the top two terminals, you have A, B & C from the top?.
Edit: Already suggested in post #22 so post #28??.
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Good morning. I got 230v on brown wire.
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