Has anyone had their central heating flushed?

[Loueytb3]

We are hopefully going to be building an extension and assuming we get planning permission will be changing the boiler. The extension is going to have underfloor heating. We have been told by the plumber that we will need to have the current pipes/radiators flushed out before changing the boiler, partly to make sure that we have the optimal efficiency from the new boiler but also because if there is any crud in the pipes, then they might block the underfloor heating. Apparently it needs to be very clean. The person he usually recommends to do this can't because his machine isn't big enough to cope with our house (its a 4 bed).

I've done a google search and there are companies that do it but I have no idea if they are cowboys or not.

Has anyone had this done and if so, who did you use?

We asked our plumber about this. He said powerflushing can cause problems with leaks. His suggestion but was installling one of these
http://www.adey.co.uk/
Magnaclean filters on the return leg of your heating to extend the life of your boiler by catching all the crud on the magnet. It was about 80 quid and our heating water comes out clear and soapy if drained - all black gunk removed.
If you fitted one in advance of your new boiler it could have a few weeks of cleaning time. Hth

I'd be wary of this. When we thought we had a problem with our boiler, we had a guy round that told us this would solve all our problems and offered to do it for what appeared to be an extortionate sum of money.

Turned out that what we needed was a new thermostat valve (for considerably less money).

I appreciate your situation is a bit different but I would be getting a second (and third opinion) from a plumber.

Thanks - I am already a bit wary. The searches I've done suggest that it is not necessary in a lot of cases, and they can charge the earth. I haven't used these plumbers before although they came recommended and have done lots of work for a neighbour. I think I need to get another plumber round. Its so hard when you don't know a good one!

We had one done by the maintenance people for the house ( Army) as our radiators had cold spots or were cold. It took most of a day but has worked and the radiators are now fully toasty