The pump keeps running Baxi solo 3 pfl 50?

It's quite likely that the PCB needs replacing. They seem to last only for about 3-4 years. For a few days, you'll hear a buzzing when the boiler is not fired up. Then the buzzing will stop but the pump will run continuously. After a week or so of that, the system will stop completely. I'm about to replace my PCB for the second time. They cost a couple of hundred quid from a plumbers' merchant. It is a job you can do yourself, but only if you feel confident enough. Rule one: make sure the whole system is switched off at the mains. Then let the boiler cool down. Follow the instructions in the manual carefully. Make sure that you only transfer one connection, or group of connections, at a time or you'll not know what goes where. If in any doubt, get a qualified plumber to do it for you.

John Brandon
March 2011

had this problem with my boiler for years only way to shut it off was to kill the power, the problem disappeared when i got a new pc board

John Farrell
January 2011

I have the same problem, Pump Not shutting down (ever) its the the relays on the pcb

Baxi sufferer
December 2010

I have a baxi solo boiler. When the central heating reaches its temperature it switches off but the boiler keeps on running sometimes at full power. This seems to hapen when the boiler has been on for some time. I have also turned the heating and water off on the landing and the boiler will continue to run. Can anyone help me as i am disabled and likely to go mad as i have had this for years and several heating people have not solved it. Also it makes a very load noise as if under pressure

wendy
November 2009

Possibly the thermostat on the hot water cylinder is set higher than that on the boiler. The cylinder keeps calling for heat but the boiler can't provide. Try turning down the cylinder thermostat.

John Brandon
January 2008