Problem with Boiler

fireice

Over the last few days a problem has developed with my boiler. There seems to be 2 things at play:

1) The boiler switches on seemingly randomly when there is no demand for water from the programmer. When this happens the "burner" light is lit or flashing and the pump next to the hot water cylinder is on.

2) Occasionally, a reasonably loud grinding/banging sound can be heard from the boiler which lasts about 20-30 seconds.

What sort of problem could this be? Are there any simple fixes? If not, how expensive is this likely to be to fix?

The boiler is an Ideal icos HE18, if any more detail is required, please say so.

Thanks

gas4you

Check any heating/hot water zone valves first.

southcoastrgi

D
you are being too kind not even metioning the "I" word

fireice

gas4you wrote: »

Check any heating/hot water zone valves first.

Are these what you are talking about? How do you check that they are the problem? (I have zero knowledge about boliers and plumbing!)

Thanks

moneysaver

fireice wrote: »

Over the last few days a problem has developed with my boiler. There seems to be 2 things at play:

1) The boiler switches on seemingly randomly when there is no demand for water from the programmer. When this happens the "burner" light is lit or flashing and the pump next to the hot water cylinder is on.

2) Occasionally, a reasonably loud grinding/banging sound can be heard from the boiler which lasts about 20-30 seconds.

What sort of problem could this be? Are there any simple fixes? If not, how expensive is this likely to be to fix?

The boiler is an Ideal icos HE18, if any more detail is required, please say so.

Thanks

Has your boiler got a pre heat function? Check the manual for this & switch if off if not needed.

That could be your number 1 question answered.

Question 2 could also be linked to this.

I am only guessing as I am not an engineer.



Moneysaver

Myser

fireice wrote: »

Are these what you are talking about?

Your link doesn't seem to work for some reason?

Here are a couple of examples of zone valves:

fireice

Yes, they were what I was linking to (I've edited the link now, sorry). How do I check if these are the problem?

The boiler does not have a preheat function, I think these are only on combi boilers. The banging sound is too loud to be normal.

Myser

Check to see if they are stuck i.e. partially closed. You can do this by setting the programmer to off for both heating and hot water then remove the valve actuator heads (metal/plastic block).

If the valve is partially closed, a small microswitch inside the actuator head may be causing the boiler to randomly fire. You will know if the valve is not fully closed as the valve body spindle won't be completely horizontal or vertical i.e. between 9 and 3 or 12 and 6 on a clockface .

fireice

Would the system need to be drained first?

I don't really feel confident about trying to fix stuff related to plumbing (don't want to flood the house!). Does anyone have any recommendations on how to find a good plumber and roughly how much this should cost to fix?

Myser

fireice wrote: »

Would the system need to be drained first?

I don't really feel confident about trying to fix stuff related to plumbing (don't want to flood the house!). Does anyone have any recommendations on how to find a good plumber and roughly how much this should cost to fix?

No the system would not need to be drained, you just remove the valve actuator head.

If you don't feel too confident, perhaps ask friends/relatives for recommendations of Gas Safe Registered people. Otherwise, you can search the Gas Safe Register.

BigCharlie

The boiler will/should only ignite if there is a heat demand. This comes from the hot-water storage thermostat, or the CH thermostat. The pump runs for two reasons, 1) there is a heat demand, and 2) the boiler case is hot, then it circulates water through the boiler to cool it down. Any crashing/banging/thumping sounds are probably due to air in the system, which will need bleeding away. There should be a bleed screw on the hot-water cylinder feed from the boiler, and on the radiators. Some heating engineers fit them to the boiler as well, but a lot of plumbers rely on the air bubbles finding their way back up the boiler cold supply pipe