Hi,
As per the thread title, I have an Ideal Logic Combi 30 and I am having a problem with the pump, which keeps activating without any DHW/DCH.
When the pump activates, it runs for exactly 4 minutes each time and this can happen as frequently as something like 5 times an hour or as infrequently as once an hour, so it's pretty inconsistent. These episodes only occur with the boiler set to Winter Mode (HW & CH) and not when set to Summer Mode (HW only).
When these pump run episodes occur:
The burner does not ignite,
I can hear water running through the radiators, which remain cold,
The display shows 0 and is free of codes,
Zero HW and CH demand,
Hot water preheat is also switched off,
DHW & DCH working fine when actually commanded.
The Grundfos pump failed early last year and it was replaced with a generic replacement as it was a mid-winter emergency and it's all the engineer had to hand on a Friday evening. I did wonder if this generic pump could be at fault as I don't recall this issue prior to replacement but I believe the pump can only operate if commanded by the boiler PCB.
The boiler is located in the house and thus doesn't have an external frost stat, although I beleive the Ideal Logic uses the return flow thermistor for frost protection in the absence of an external stat. I also believe a faulty thermistor would give a code if faulty or fire up the burner if it thought frost was a potential issue, and it's not firing the burner, just running the pump.
The only other change since the pump was replaced is the addition of a Honeywell R8810 Opentherm relay as I already had Evohome running with a BDR91. Opentherm works fine plus I can't imagine this would be running the pump without firing the burner if faulty.
Any ideas as I'm at a loss as to where to go with this - the only thing I can think of is a faulty PCB as the PCB fuse had to be replaced when the pump failed and blew it? I'm just a home owner with little knowledge, so fingers crossed the more knowledgeable of you might have an idea what's going on.
Thanks in advance for any help.
As per the thread title, I have an Ideal Logic Combi 30 and I am having a problem with the pump, which keeps activating without any DHW/DCH.
When the pump activates, it runs for exactly 4 minutes each time and this can happen as frequently as something like 5 times an hour or as infrequently as once an hour, so it's pretty inconsistent. These episodes only occur with the boiler set to Winter Mode (HW & CH) and not when set to Summer Mode (HW only).
When these pump run episodes occur:
The burner does not ignite,
I can hear water running through the radiators, which remain cold,
The display shows 0 and is free of codes,
Zero HW and CH demand,
Hot water preheat is also switched off,
DHW & DCH working fine when actually commanded.
The Grundfos pump failed early last year and it was replaced with a generic replacement as it was a mid-winter emergency and it's all the engineer had to hand on a Friday evening. I did wonder if this generic pump could be at fault as I don't recall this issue prior to replacement but I believe the pump can only operate if commanded by the boiler PCB.
The boiler is located in the house and thus doesn't have an external frost stat, although I beleive the Ideal Logic uses the return flow thermistor for frost protection in the absence of an external stat. I also believe a faulty thermistor would give a code if faulty or fire up the burner if it thought frost was a potential issue, and it's not firing the burner, just running the pump.
The only other change since the pump was replaced is the addition of a Honeywell R8810 Opentherm relay as I already had Evohome running with a BDR91. Opentherm works fine plus I can't imagine this would be running the pump without firing the burner if faulty.
Any ideas as I'm at a loss as to where to go with this - the only thing I can think of is a faulty PCB as the PCB fuse had to be replaced when the pump failed and blew it? I'm just a home owner with little knowledge, so fingers crossed the more knowledgeable of you might have an idea what's going on.
Thanks in advance for any help.