Put new valve in works fine, only thing is that it cuts the CH off when the HW tank reaches a certain temp. I don't think this should happen, do you think it was wired correctly as I have swapped the. Wires colour for colour. And the valve is the same way around.
possible T valve problems???
- Thread starter BigHammo
- Start date
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I though it might not be the valve, which is why I asked.
Anyway what you describe shouldn't happen, so I see two possibilities, both will give the symptoms you describe, but number 1 is probably the most likely.
1. If the valve is not positioning itself in the 'heating only' position, check that there is a hot water off signal on the grey wire. This will come from the programmers 'hot water off' terminal and the 'satisfied' signal from the cylinder thermostat. I suspect that the 'hot water off' signal from the cylinder thermostat is missing, so that when the hot water thermostat switches off, it doesn't put a live on the grey wire to wind the valve fully across to the heating only position.
or.
2. If the valve is positioning itself in the 'heating only' position but the boiler isn't running when it's there, check for a live output on the orange wire. This orange wire is what is responsible for running the boiler and pump when only the heating is required. The orange wire should connect to the boilers switched live supply. Which will be linked to the hot water cylinder thermostats 'call for heat' terminal also.
Are you absolutely sure nothing else has been disturbed?
Anyway what you describe shouldn't happen, so I see two possibilities, both will give the symptoms you describe, but number 1 is probably the most likely.
1. If the valve is not positioning itself in the 'heating only' position, check that there is a hot water off signal on the grey wire. This will come from the programmers 'hot water off' terminal and the 'satisfied' signal from the cylinder thermostat. I suspect that the 'hot water off' signal from the cylinder thermostat is missing, so that when the hot water thermostat switches off, it doesn't put a live on the grey wire to wind the valve fully across to the heating only position.
or.
2. If the valve is positioning itself in the 'heating only' position but the boiler isn't running when it's there, check for a live output on the orange wire. This orange wire is what is responsible for running the boiler and pump when only the heating is required. The orange wire should connect to the boilers switched live supply. Which will be linked to the hot water cylinder thermostats 'call for heat' terminal also.
Last edited:
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