Post summer first time use of CH and problem

[hoppaz]

We have had our CH off for the summer and finally came to use it last night due to the colder temperatures. The boiler fired up and the pump went on no problem but the radiators didn't heat up too much.

So after a couple of hours I went to check the pump and the danfoss electronic 3 way valve and found that it felt like it was sticking I moved the switch back and forth and this seemed to free up the valve and it enable to radiators to heat up.

Now this morning I came down to find the fused 3A wall socket was off even though it was switched on so I replaced the fuse and it lighted up again and the CH and HW wall control came back on. Now as soon as I try to slide the control to ON for either HW or CH the fuse in the socket blows.

Any ideas???

I have a baxi back boiler and had a new CH pump fitted about 12 months ago.

 

[gas112]

Take the cover off the 3 port valve and see if its damp in there

 

[hoppaz]

Right I took the cover off the pump to isolate the live and could smell like some electronics had been cooking. There is a capacitor just under the cover which appears to have baked and leaked a little.

I isolated the pump's live and turned the 3a power supply back on and both the CH and HW work via the controller which fires up the boiler without blowing any fuses.

My next question is what could cause the pump to burn out so quickly? When the pump was changed the system was drained, ran with cleaner, flushed and then ran with inhibitor.

It is just over one year old (although doesn't appear to have a name on it) and all of the other wires were connected inside with clean connections.

 

[hoppaz]

Take the cover off the 3 port valve and see if its damp in there

Just checked and its dry with good soldered connections (no sign of damage etc)

I have also just checked the junction box where all of the pump, valve, hot water tank wiring comes from and all looks good with no loose wires or bad / burnt connections