Icos boiler loud thump

[Dazzerdon]

I have a Icos HE18 boiler in a cupboard which was fitted just under a year ago. It does my heating and heats a hot water cylinder tank. Lately in the mornings as the system comes on with the timer within a couple of seconds of the boiler igniting, there is a loud thump noise that occurs. I seem to have noticed if the system is left on for most of the day the thump noise reduces over time as the boiler cuts in each time. Its a bit worring any idea's?

 

[gas4you]

Call Ideal under warranty as it is still so new.

 

[diverdee]

is it just as the gas ignites if so get gas pressures checked.only thing else have known to cause this is on a vertical flue installed faulty.with ally collar upside down n after awhile u get crossover on the flue

 

[screech]

a faulty seal on the top of the heat engine where the flue connects can cause it to make a noise at start up but it sounds more like a bus is idling right by your head or it could be the spark electrodes have warped, a very common fault. means the spark is weaker therefore takes longer to light, more gas to light, boiler goes thump.

 

[Gas2Air]

I have a Icos HE18 boiler in a cupboard which was fitted just under a year ago. It does my heating and heats a hot water cylinder tank. Lately in the mornings as the system comes on with the timer within a couple of seconds of the boiler igniting, there is a loud thump noise that occurs. I seem to have noticed if the system is left on for most of the day the thump noise reduces over time as the boiler cuts in each time. Its a bit worring any idea's?

Icos. Needs full service.

 

[Dazzerdon]

is it just as the gas ignites if so get gas pressures checked.only thing else have known to cause this is on a vertical flue installed faulty.with ally collar upside down n after awhile u get crossover on the flue

We did get a problem about 2 months after it was installed where there was a loud thumping noise that went on for quite a while we turned it off straight away. We got our cover engineer out and he said it was to do with the rubber collar (I think its rubber) between the boiler and the vertical flue, he managed to ease it back down abit, as it had moved upwards inside the boiler case and the noise went away. I can't be sure if this is the same problem, just not as severe.

 

[shambolic]

It could be same thing. Air gas mixture problem or flue gases coming back in with air if flue doughnut not fully home

 

[Dazzerdon]

It could be same thing. Air gas mixture problem or flue gases coming back in with air if flue doughnut not fully home

Why would it go away the longer the system was running as per my original post. As I sit typing the boiler has just ignited and the noise is still there but it is very very soft thump which if you didn't know what you were listening for you wouldn't notice it. There is a definite gap between the sound of the ignition and the other noise of about 5 seconds.

 

[diverdee]

still sounds to me as thou flue is only just sealing.if it continues ask your guy to check how far inner flue is going into boiler seal. the collar has a taper which if in right allows more of the inner pipe to enter .the reason its gets less when warm is probably expansion hence sealing better

 

[Dazzerdon]

Thanks for all your in put. I've got a engineer coming out tomorrow, whats the odds my "thump" sound will go shy and not be heard?
I'II post again after with the out come.

 

[Gasman28]

It could be the ignition electrodes. Loads of faults on these, sometimes due to poor condense pipe installation.

 

[shambolic]

If it noisy after it lights it could be an overheating issue rather than boiler problem although this would take a wee while to show once up to temperature.
It defo sounds like air gas which will change as the boiler heats up too as the gvl will modulate down as the fan speed reduces causing less gas to be drawn in.!