Power Flush really required?

My Alpha CB24 combi was playing up recently with the boiler cycling on and off while using the hot water. Then there was a breach presumably in the heat exchanger with the mains water getting into the heating circuit. This was evident because the pressure gauge shot up to mains pressure. Got the service company in and they said before they can service/repair the boiler a power flush will be required, because the heat exchanger is getting clogged with sludge.

It turns our this is quite costly, and for the following reasons I'm unsure if this is really required.

>The radiators don't show any sign of significant sludge, such as colder at the base or taking a long time to heat up.
>2 of the 5 rads have been recently removed (for decorating) and I washed them out.
>I also replaced one of the rads recently.
> One is a towel rail I installed about 2 years ago, with the bottom connections I don't see how sludge could collect in this.

That leaves only one rad that hasn't been touched for a number of years. Surely I can just take this one off and flush it through with the hose? Sure, debris may have run through into the other rads, but it would be pretty straight forward to take off all the rads and flush them in one go. Why not just do this? Possible issues I can think of is magnetite & build-up of limescale, though I did flush the system with Kilrock K03 cleanser 2 months ago.

who's the service company and what evidence have they produced that you need a powerflush?

Your lucky that they are dealing with the boiler as alot of other manufacturer would have washed there hands of it.
They all state in there install instruction that the system should be cleaned to british stds, however this is acheive.
1-contact installer and get too rectify as they should have done it(unless u didnt want too pay for it).
2-Alpha wont keep repairing,get it done before it leaves u with an unwarenteed boiler.
The cost of a power flush is less than another boiler.
also a clean system is more efficient.
Hope this helps
Obviously this is assuming the system is dirty-Good advise above as this is also used by alot of manus to get out of warenty repairs/make xtra money!

oooh you deffo need one

ive got to pay for this expensive bit of kit somehow

Thanks for the replies. Service company I mean the engineers contracting on behalf of Alpha. They cleaned out the heat exchanger which meant the hot water worked again for a few days. They said the power flush is required before they can come and look at it again.

I've read on some sites that you can use mains water to flush the system and you need to do it once on the flow and once on the return. But my central heating system is quite small (and I don't have carpets that could get stained with sludge) so it would be just as easy to take the rads off. I'm just wondering if there is a reason why not?

If the plate was blocked then there is dirt in the system.

Howeverdepending on how bad it is it msy be better to deal with plate when its blocked.

Tony

sounds like a fair cop tbh, they've come and cleaned it once and obviously wont do it again under warranty. Its up to you whether you get it proffessionally cleaned, do it yourself or do nothing. All you need to realise is that any faults caused by sludge/magnetite debris wont be covered.
wheres the installer in all this? its his fault really if he hasnt flushed it properly.

If costs an issue take the rads out and flush individually, run a cleanser through then fit a filter and bang in some inhibitor mate

If u don't wanna cough up for power flush then just stick magna clean on fill it up with descaling agent leave it for week with heating on, drain system fill system and clean magna every 2-3 days until clean

A standard full powerflush would probably be overkill on this one, but by the time a plumber took the extra rad off and flushed it, & sent the mains round the rest , he'd be spending a few hours.
A DIY job should be fine. I'd flush out your dirtiest rad(s) by inverting in the garden, put some Fernox F3 in for a week, flush with the mains and add inhibitor. Magnetic filter is an extra £100 - see how dirty it is at the flush stage.

Hey thanks everyone for the most helpful replies.

The boiler is way past it's warranty. I've paid for the engineer to fix the boiler. They told me later that the first visit was to mainly to assess the problem and they will come back when the system is flushed. I'm just putting this in writing to state I have no problem with the Alpha contract engineers. Of course they're not going to recommend DIY procedures to the public, then they're taking some responsibility if it goes wrong.

I will definitely DIY it. It's cheaper for me to take a day off work!

We dont know how bad it is.

It might be possible to do it with just with a chemical cleaner.

Most cover schemes want to see a professional receipt for powerflushing.

Tony

Tony you're right there, I did need a professional receipt after all. Wasn't in the fine print but obviously they can insist on this (obvious in hindsight!).

The powerflush sorted the problem and we didn't need the boiler people at all. Expensive lesson!