combi boiler time to ignite

[greencoat]

Hi all,
got a Worcester Bosch 230 , around 8 years old. Been fine with no problems at all.
Today I've noticed that when you turn the hot tap on as we normally would, it doesn't ignite. You have to turn the tap on fuller for the boiler to ignite. We do get hot water then, but because the tap is on a fuller flow , I'm sure it won't be as hot.

Is this an indication something's on it's way out?

Cheers,
Pete

 

[caterhamplumbing]

Has the boiler or your home have a scale reducer. It sounds as though there may be some limescale build up in the boiler reducing the flow rate through the boiler. Most Combi require a minimum flow rate to start the ignition process.

 

[ChrisR]

Could be the Diaphragm in the Diverter Valve.
Turn CH off and wait until boiler is cool, turn HW on full so it lights. Feel the leftmost fat pipe under the boiler. If it starts to get hot, that confirms it. Not a mammoth job but a bit beyond diy.

 

[greencoat]

Thanks for replies, in work last night so only just read them.


there's no scale reducer in our house or boiler, but none of our friends or family have one either. (In Merseyside). Do we Northeners need them?

I'm just letting the C H cool down to check that pipe as you say. Previously, i'd asked my uncle about it (who fitted it) & he said that you wouldn't bother replacing a diaphragm, you'd just replace the boiler. ( Don't know cost on diaphragm job, so can't compare it to replacement costs)


Cheers,
Pete

 

[ChrisR]

you wouldn't bother replacing a diaphragm, you'd just replace the boiler

Tough call. Work for BG does he?

 

[greencoat]

Actually no, he's just a plumber. Makes it sound like he's doing me a favour also.


I just don't know what to do really.

From what I've read so far, it could be the diaphragm, or blocked/scaled up domestic heat exchanger. <edit ... or would the reset pop up if it was the heat exchanger ? end edit>

I tried the full flow chek & the pipe didn't seem to heat up at all.

Cheers,
Pete

 

[Softus]

Could be the Diaphragm in the Diverter Valve.
Turn CH off and wait until boiler is cool, turn HW on full so it lights. Feel the leftmost fat pipe under the boiler. If it starts to get hot, that confirms it. Not a mammoth job but a bit beyond diy.

I don't mean to be impertinent Chris, but surely if the boiler doesn't go into ignition then it's either scale causing poor flow or the flow switch not actuating as it should, or both?