Baxi Solo 3 30PF Boiler problem

[simondjuk]

Hi everyone, I need some advice on our boiler which is playing up.

Its a Baxi Solo 3 30PF, is about 12 years old and is serviced regularly by British Gas

So far we have had British Gas out 4 times (under Homecare) and each time the issue isn't fixed so i'm wondering if anyone on here might be able to point us in the right direction so when they visit again we might be able to suggest something they haven't looked at. So far they have changed to PCB, 'cut and remade live connection at fan block' (on BG paperwork) and changed the thermistor.

Basically the pump is staying on when the heating and hot water is off, even by switching it to 'off' on the timer. When you increase the thermostat on the wall and it clicks, it takes about 30-45 mins for the boiler to start up and when you turn it down again so it clicks, the boiler stays on but eventually goes off. An example being on Saturday morning, we turned the wall stat up at 8.05 and at 8.47 the boiler started. While my OH was in the shower this morning the water started going cold and then the boiler started up which leads me to think some kind of thermostat problem somewhere.

Any advice appreciated

Many thanks

 

[BLOD]

When you switch off at the thermostat or programmer it's normal for the pump to keep running, but it should turn off after a few minutes.
If nothing happens when you switch on at the programmer and the thermostat is calling for heat then you need to get someone who can fault find with a multimeter, I'd probably start with the motorised valve (s)

 

[vern]

I'd probably start with the motorised valve (s)

If PCB has bee changed and is good.....exactly as Blod says

 

[mfgs]

They have a pump overrun so the pump stays on for about five minutes after the boiler has stopped, if it runs non stop then it is usually a pcb problem with these boilers.
The other problem sounds more like a controls problem and more than likely the motoised valve

 

[TBServices]

Serviced by British gas? May as well say it's never been serviced then.

 

[vern]

One of my customers thought their FGA was a mini Hoover:rolleyes2:

 

[mountainman]

One of my customers thought their FGA was a mini Hoover:rolleyes2:

It isn't? 😳

 

[simondjuk]

6 visits later and finally sorted. Turns out it was the air pressure switch.

Is this an obvious fault and fairly easy to diagnose?