S
skatesy
I have an Alpha conventional boiler with Y Plan. Up to recently, both CH and HW worked fine but the HW would go off occasionally. Switching the main supply off and on seemed to fix that for a while.
But now the HW seems to have packed up completely. I have checked the wiring and have done as many checks as I can. Both room and cylinder thermostats seem OK. I have checked the power to terminals under different condition and there always seemed to be an anomaly that did not match the circuit diagrams. After much checking, I found that, T6 (from HW-on, going to C on cyl stat) and T7 (from HW-off, going to 2 on cyl stat and grey to motorised valve) were both powered. Perhaps T7 (HW-off) is cancelling T6 (HW-on)?
I disconnected the lead from HW-off to T 7. The motorised valve went to the mid position (A+B) but the boiler did not fire. I reconnected the lead, CH came on the valve motored to the B position, CH came on but no HW.
With heating and water calling I get power on Terminals 4,5,6,7 and 8. All this seems to indicate that the programmer is at fault and sending out both HW off and on signals but I would like to confirm this before paying £90 for an Alpha programmer.
Initially I thought that the motorised valve or motor were faulty but they seem to be moving OK and I would rather not waste £100 on replacing them without curing the problem plus the bother of draining the system.
Any help or advice gratefully received
But now the HW seems to have packed up completely. I have checked the wiring and have done as many checks as I can. Both room and cylinder thermostats seem OK. I have checked the power to terminals under different condition and there always seemed to be an anomaly that did not match the circuit diagrams. After much checking, I found that, T6 (from HW-on, going to C on cyl stat) and T7 (from HW-off, going to 2 on cyl stat and grey to motorised valve) were both powered. Perhaps T7 (HW-off) is cancelling T6 (HW-on)?
I disconnected the lead from HW-off to T 7. The motorised valve went to the mid position (A+B) but the boiler did not fire. I reconnected the lead, CH came on the valve motored to the B position, CH came on but no HW.
With heating and water calling I get power on Terminals 4,5,6,7 and 8. All this seems to indicate that the programmer is at fault and sending out both HW off and on signals but I would like to confirm this before paying £90 for an Alpha programmer.
Initially I thought that the motorised valve or motor were faulty but they seem to be moving OK and I would rather not waste £100 on replacing them without curing the problem plus the bother of draining the system.
Any help or advice gratefully received
