- 10 Oct 2011
- Reaction score
Would it be a grundfos UPs2 pump that was fitted??
The effect of this was ( surprisingly ) to increase the voltage across the coil. As more turns shorted, the effect became worse and eventually blew the PCB. Just replacing the PCB would cause the new PCB to blow again if the gas valve was not changed!
Bernard. I spent some 25 years working with relays and ~~~~~~~..I would like to think I know a little about relays
I think it is a grundfos alpha 2. It has three speed settings, auto adapt, and a display showing the pump speed. It is currently set to auto adapt, it is hard to see the size of the pump as it is behind my hot water tank.....awkward as hell, one of the reasons I didn't replace it myself!Would it be a grundfos UPs2 pump that was fitted??
I think the reason my gas valve was changed was due to water damage from a storm that blew rain water into the boiler, it was across the top of the boiler as well. Bearing that in mind, it could have damaged the PCB requiring it to be replaced also. As I said before I was away from home when the repair was done.Failure to maintain the correct tension during the winding of coils can and does result in failure of the coil due to insulation being abraided. This occurs during manufacture if tension is too high and occurs later if tension was too low when winding.
Impedance tests normally ( should ) detect shorted turns during Quality Assurance testing. Hence windings that are over tight do not normally get into equipment. . Slack wound colis can fail after years in service when turns have been moving against each other due to changing magnetic fields.. ( transient when DC supply is switched, continuous when coil is fed with AC. )
Try setting the pump to a fixed speed , max is probably best and see how that makes your boiler behave, your boiler like most of that age were not designed to have a modern modulating pump fitted, and some boilers struggle with the pump electronics, the early Grundfoss ones did damage PCBs and needed a special supply lead to protect boiler pcbsI think it is a grundfos alpha 2. It has three speed settings, auto adapt, and a display showing the pump speed. It is currently set to auto adapt, it is hard to see the size of the pump as it is behind my hot water tank.....awkward as hell, one of the reasons I didn't replace it myself!
It was intended as background knowledge about the various failure modes that are known to have affected the reliability of some gas valve / PCB combinations.Bernard, your post throws no light on faulty gas valve possibly killing the pcb
can u see a twelve way connector on the PCB ??
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