boiler issue

[jackfoley]

hi

sometimes the heating does not come on. The heating light is flashing on the boiler. i can hear the boiler running whilst this is going on.
all i need to do is press reset and then it seems to fire up.
But when it fires up i hear the tic tic tic sounds three or four times. Could it be an issue with ignition?
Happens once a week. boiler is a worcester 28si.
any ideas?

thanks

 

[Agile]

It does sound like an ignition issue.

Apart from inspecting the ignition lead at the PCB end we cannot give you further advice aoart from calling a gas engineer.

When was it last serviced?

Tony

 

[jackfoley]

january 2011.
it all started a couple of weeks back.

 

[Agile]

In that case if it was PROPERLY serviced, opening it all up, then I would advise that you call the service engineer back as it sounds as if he did not set something correctly or left the HT lead loose.

Tony

 

[jackfoley]

what is the HT lead?

 

[Agile]

High Tension lead.

It takes the 14,000 V voltage from the PCB to the spark electrode.

Tony

 

[simond]

I can't see what wasn't set properly Tony in a Worcester 28? This is not a boiler full of adjustments is it?

After all, the boiler ran OK for nearly 10 weeks afterwards.

 

[Boilerman2]

Quite right Simon!!
I will only accept a "Recall" if the original job was within a Calendar month
I think 2 months is pushing it for a recall things do go wrong!!

 

[Agile]

There are so many things which could have stopped it igniting reliably.

Mix, gaps, HT lead connections, dirty insulators etc.

We have all been to many cases where someone has not done something they should have.

I was called to a premix giving 155 PPM of CO after he had spent two hours with the boiler the day before. Within ten minures I had it at 39 PPM.

Jan 31st to 3rd March would be little mover one month.

Until its been diagnosed we dont know but if I did betting I would place odds at 3:1 thats its something that has been omitted, mis-set or disturbed.

Tony

 

[jackfoley]

update on this.

Worcester came out yesterday and the guy said that the "flame detector"had snapped out of place. It looks like a plastic tube with a wire running in it.

He did not carry the part so he adapted one from a greenstar boiler.

Guess what, this morning same problem, central heating light flashing and no flame on.

Press reset and it kicked in.

Note that this aonly happens when the boiler has been off a few hours.
During the day it comes on and off according to thermostat.

Could it be a pressure issue ie pressure dropping after a few hours it has been off?

thanks

 

[adamsheating]

what is the pressure gauge set at and how often are you having to top up?

 

[adamsheating]

I can't see what wasn't set properly Tony in a Worcester 28? This is not a boiler full of adjustments is it?

After all, the boiler ran OK for nearly 10 weeks afterwards.

Adjusting a gas valve by quarter of a turn could increase or decrease the CO output by unknown quantities, rendering a boiler either safe of immediately dangerous. It is essential that the installer know what he is doing.

 

[jackfoley]

i have had to put some water in a couple of times in the past week.
in the morning it is about 0.9 1 bar. In a nutshell it does seem to lose a little bit but i thought that at 0.9 it would still work.

i have looked for leaks in the house but no sign.

 

[adamsheating]

i have had to put some water in a couple of times in the past week.
in the morning it is about 0.9 1 bar. In a nutshell it does seem to lose a little bit but i thought that at 0.9 it would still work.

i have looked for leaks in the house but no sign.

I was just wondering if it was venting due to an expansion problem, then falling below the required pressure level?

To check expansion, turn boiler on full blast and see if the pressure gauge rises sharply, usually takes 5-15 minutes.

 

[jackfoley]

do i need to do this test after it has been off a few hours?