Boiler Firing Frequently

[fouxdafafa]

Hi again,
After my problem of a few weeks ago, where my boiler wouldn't fire at all, it's now behaving strangely - I think. It's an Ideal Classic, and I had the fan replaced and a service done after my previous issue. Now, what I notice is that, when heating is required, the boiler fires for around a minute and then shuts off - and not because the room stat has turned it off (because I don't hear the audible click from the room stat, and it's below the set temp anyway). It does this repeatedly, coming on and then going off. I don't remember it behaving like this before. I assume that it's switching off because it's reaching the temp set on the boiler itself (it's on number 5 out of 6). Is this normal behaviour?

The only other thought I had was that it's switching off because it think it's not venting the waste gases properly (had that problem in the past when the flue was blocked by snow).

Any thoughts?

 

[Hugh Jaleak]

Is the heat getting away from the boiler? If the heat cant get away then boiler will cut out as it'll quickly reach set temp. Circulation problem, possible faulty pump.

 

[Agile]

Was it a genuine Ideal new fan?

I am suspicious about that.,

But as Hugh says the first thing to check is the pump is working and the flow and return are both geting warm.

Tony

 

[fouxdafafa]

Can't confirm whether the fan was a genuine Ideal. The work was done when I wasn't at home. Could have a look inside I suppose. One thing I have noticed is that there's quite a noticeable hum from the fan now.

Pretty sure the pump is OK because all the radiators get hot. It's just this annoying cycling on and off of the boiler without the room stat clicking off.

 

[Agile]

Are you at all sure that another fan was even fitted?

There are some cowboys who would lubricate the old fan and charge you for a new one!

Some would even take to old one out to their van and return with the old one an a box!!!

One of my customers even had someone who took the old Biasi fan out and returned with it in a GlowWorm box. By chance she used to live opposite the GlowWorm plant in Derbyshire. She questioned him but he did not reply. He charged her about £350 to refit the old fan. I had to charge her about £198 to fit a new Biasi fan.

Tony

 

[fouxdafafa]

Well, as I said, I wasn't at home when the work was done, but the company is well established locally so I'd surprised if they did something dodgy. I know that's no guarantee though. All I can say is the new fan hums, whereas the old fan didn't, but the old fan at times sounded as if it was on its way out.

I'm not sure, but it could be that as part of the service, the temperature setting on the boiler may have been turned down a little. Would that cause the behaviour I described?

 

[Hugh Jaleak]

Is the heating actually working?

 

[fouxdafafa]

Yes, heating is working.

I have it on at the moment, and it's behaving as I described. The boiler fires but it only stays on for about 45secs, then stays off for about 90secs, then fires again. And it's doing that repeatedly. And it's not the room stat that's causing it to stop firing.


.... Having said that, the room stat has just clicked off, but the boiler's been cycling on/off for a while.

 

[Hugh Jaleak]

Pump seems to be working ok then. Does boiler demonstrate this behaviour constantly? (i.e. Starting from cold when its switched on.)