Pump/Timer Issue

[Zambo]

Although my problem appears to be an electrical one, I'm posting in this section because it relates to my central heating and hot water system. Any help or guidance would be appreciated.

Boiler - Baxi Solo 2 50PF

Pump - Grunfos Selectric

Timer - Danfoss FP15

Symptoms

Pump runs 24/7 - was informed that this is likely to be a pcb problem. As an initial temporary solution, although it became a permanent one, I put the pump on timer using a timer switch, so it only came on when the water and heating was due to come on.

This worked fine for quite some time, but then I noticed that the numbers on the timer dial were getting faint when the boiler/pump was off, and then they just went out, and the boiler was not coming on. However, as soon as I switch the pump on, the dials lights up again but I have to reset the timer. I have now dispensed with the timer on the pump, and all is working OK accept of course the pump is on 24/7.

Anyone got any ideas why the pump being off makes the timer dial go faint and then eventually go off now, when it didn't beore? Cheers

 

[45yearsagasman]

No idea as to why the timer display is fading, but you should get the pcb replaced as it controls pump overrun on your boiler and without it you could damage the heat exchanger. 10 out of 10 for ingenuity though

 

[Zambo]

No idea as to why the timer display is fading, but you should get the pcb replaced as it controls pump overrun on your boiler and without it you could damage the heat exchanger. 10 out of 10 for ingenuity though

Yeah thanks, I was just trying to hang out and avoid a sizeable bill. I'm still intrigued as to what has happened to the system timer though. The cable from it runs into the Danfoss junction box along with the cable from the pump and diverter valve. As soon as the socket with the pump in is switched off, the digits on the timer start to fade, and then go out leaving it useless. As long as the pump switch is on, whether the boiler is alight or not, the digits show up as they should do.

I'd better phone my gasman.