Plumber/gas fitter w. combi boiler experience

I'm looking for some one with experience of combi boilers; my own plumber is very good, but freely admits he's not sure about combis.

Its needs a service and from googling the symptoms I think the Heat exchanger needs to be descaled or replaced.

can anyone help?

sure give me a call for advice, or ask your question here

what area are you in, may know some installers there

imho, there is very little difference in heat only and combi boilers, only a few extra parts (plate to plates,extra heat sensors, a diverter)

Thanks for your help - my plumber's a little unsure about combi boilers and he's something of a perfectionist (not necessarily a bad thing!).

What's happening is that I'm getting very, very hot water (i.e. make a cup of tea hot) and then cold water, then hot again.

When running the tap in the kitchen I can hear the boiler come on & then go off again, where it should be running all the time so long as the tap is open.

I've googled a bit & it sounds like the heat exchanger is the problem - is that difficult to fix?

you plete to plate heatexchanger is scaled up (assuming its not a dual pass exchanger) or the filter in the incoming mains to the boiler is blocked

what boiler is it, plate to plates are not expensive for most

Thanks - it's a Ferroli boiler.

Do you think its a fairly straightforward job?

depends, if it a ferroli modena, then that has bi-thermal heat exchanger, in other words both your central heating heat exchanger and your dhw exchanger are one piece and the whole lot would have to be changed (not sure the price, but not cheap, ring heatovent for a price)

very worthwhile that the incomming mains filter under the boiler is checked first, if your plumber has a power flusher, the could try connect that to the dhw in/out and add a flushing agent, leave it operate for a good few hours (i would leave it all day) and see does it flush the exchanger, but this is not always successful.

http://i873.photobucket.com/albums/ab297/TonyGordon/untitled.jpg

very useful advice, thank you
Will let you know how he gets on

Just to update on this (and many thanks for your advice); my plumber brought over a boiler expert and between them they descaled the heat exchanger.

It took 24 hours and and E150 but I have a working boiler / proper hot water and shower again!

So I guess I just have to build that in as part of the a regular service.

Have a water softener fitted instead to treat the water before it does the same again to the heatexchanger