Baxi Solo Overheat Problem

[Al Growler]

Boiler started to run for a while then switches to overheat mode. Thinking maybe stat, pump or airlock. Bled rads recently no air, so maybe one of the first two? It's an old timer (19 years) regularly serviced and maintained but I guess they don't last forever.

Would be grateful for any advice. Thanks.

Al

ps meant to say rads are hotter than normal

 

[Terrywookfit]

Which model ??

 

[Al Growler]

2 PF

 

[ironsidebod]

Check the pump is working first of all.

Has anyone changed the setting under the small panel (the bit that pulls off)? The dial controls the temperature output.

 

[Al Growler]

No changes to settings. Boiler is on about three quarters capacity. Pump working.

 

[Al Growler]

A couple of other developments on this. One of the radiator back panels was cold, so I bled that and got loads of air out, but boiler still switching to overheat. Also there is a slight vibration from pump with boiler off (pcb?) although the pcb is only a couple of years old.

One question re pump which is a Grundfos. It appears I have 3 speeds on the pump, but I can't see the settings. I have a dial which looks like a screw, and the groove is pointing to 6 o'clock. If it's a pump problem is there any point turning it up for a short term fix, and if so is it anti-clock to turn up?

At the moment I have to keep turning boiler on and off to get hot water/heating

Thanks again for any help.

edit: sorry, pump only runs when in overheat mode, it is silent when boiler off.

 

[Al Growler]

Temporarily sorted this by simply turning the boiler stat down from around 3/4s to just under half way and that has stopped it going into over heat. Fortunately it hasn't affected hot water set to 60 degs or rad temp.

However this is probaby masking real problem which I guess could still be a number of things. As the boiler is an old timer will prob go for a new one after Christmas, as spending on this one is likely to increase.

 

[ironsidebod]

Our old PF60 used to run at a setting of 3.5 on the boiler with the pump on speed two for 16 radiators and hot water.

Does yours really need to be set so high?

Not sure why you'd rush to replace, there's not a lot to them and parts are easy to get. We had bother with ours but a power flush sorted it, you're going to need this for a new boiler anyway. The only other thing I had to do was repair the PCB (needed reflowing, the solder joints go bad).

 

[Al Growler]

Yeah, whilst it's working OK the temptation is there to keep it. Have spent money keeping it going over the years, and if it was say 5 years old now, I'd be inclined to try to keep it going. Will think about it for a few weeks and make a decision after Christmas.

re the setting, just had left it after the last service. I assumed the engineer would leave it at appropriate number. My thinking is if it worked OK on that setting for so long, why has it suddenly gone into overheat now. Working fine now on half way point, giving hot rads and hot water. Still got pump on max, so might turn that back down a notch and see what happens.

Cheers for the comments and advice.