I finally sorted out everything on the Halstead Quattro, except for putting on a new diverter valve, since the old one was seized and not responding to working with silicone.
After refilling and bleeding the heat exchanger, tried to fire up, but no heat.
The pump is working fine, and both central heating and hot water demand switches on the pump, but no more. There is no current going to the fan, and no spark to the burner.
The Halstead Fault Finder gets as far as the overheat cut off device and the over-run thermostat. I've never had any trouble before with either of these devices, and I didn't go near them this time. Even when the diverter valve was playing up, they cut in at 85C and operated the pump as they should. The wiring to them is fine, and I'm running out of ideas.
Is there some way of over-riding them momentarily so I can test them? What else is likely to be between the pump and the fan? I think the fan has to operate before it will trigger the ignition.
If it was the circuit board, surely the fan would run, and there would be no ignition?
In this weather, I really would like a hot shower, and cannot wait or afford to wait until after Christmas for a fitter.
Update: the two control stats are dry, seated on top of the heat exchanger pipework. The overheat thermostat's two terminals are open circuit. The pump overrun is closed between 1 (black) and 3 (brown) and open to 2 (red). All three go to the driver board. Mechanically the overheat rod is as far down as it will go, so I presume this means it is reset.
It feels as if there is a fuse blown to the entire Ignition PCB, since everything connected to this seems dead. Next thing is to test the brown feeder wire...
...Power is definitely getting to the ignition board, but definitely not to the fan. It does suggest something needs to be reset.
I whipped the ignition board to have a look at it - no obvious dry joints or closed circuits, and it is only 3 years old, so shouldn't have failed yet. Still hopefully hunting for anything that got unplugged.
After refilling and bleeding the heat exchanger, tried to fire up, but no heat.
The pump is working fine, and both central heating and hot water demand switches on the pump, but no more. There is no current going to the fan, and no spark to the burner.
The Halstead Fault Finder gets as far as the overheat cut off device and the over-run thermostat. I've never had any trouble before with either of these devices, and I didn't go near them this time. Even when the diverter valve was playing up, they cut in at 85C and operated the pump as they should. The wiring to them is fine, and I'm running out of ideas.
Is there some way of over-riding them momentarily so I can test them? What else is likely to be between the pump and the fan? I think the fan has to operate before it will trigger the ignition.
If it was the circuit board, surely the fan would run, and there would be no ignition?
In this weather, I really would like a hot shower, and cannot wait or afford to wait until after Christmas for a fitter.
Update: the two control stats are dry, seated on top of the heat exchanger pipework. The overheat thermostat's two terminals are open circuit. The pump overrun is closed between 1 (black) and 3 (brown) and open to 2 (red). All three go to the driver board. Mechanically the overheat rod is as far down as it will go, so I presume this means it is reset.
It feels as if there is a fuse blown to the entire Ignition PCB, since everything connected to this seems dead. Next thing is to test the brown feeder wire...
...Power is definitely getting to the ignition board, but definitely not to the fan. It does suggest something needs to be reset.
I whipped the ignition board to have a look at it - no obvious dry joints or closed circuits, and it is only 3 years old, so shouldn't have failed yet. Still hopefully hunting for anything that got unplugged.
