Old heating system and back boiler - power flush?

[MichaelFinnigan]

PIL have kindly given us £500 as a wedding gift with the proviso we spend it on the house
Our heating system is ancient and they've suggested a boiler service and power flush

Our radiators have cold spots. Last year we took off the worst, cleaned out the gunk and put inhibitor in the system

Would we be able to do do a flush and service for £500

I'm a bit worried that our boiler may be beyond a simple service

We can't afford to add anything to the £500.

Would this be a sensible use of the £?

There are about 1000 things that need doing to the house so we could easily spend it elsewhere while continuing to ignore save for the heating system

[Haribolover]

Had a power flush in a previous house and it made a huge difference to the heat coming from the radiators. System was full of limescale.

[MichaelFinnigan]

Thanks haribolover can you remember what it roughly?

[MichaelFinnigan]

Cost? Sorry

[specialsubject]

no point if you have microbore pipes - do you?
you can do a chemical flush for about £20 worth of chemical and some time and effort. These are gentler on older systems.
if it is an oil boiler, it must be serviced annually. If it isn't - well, it may not be worth it, although I would spend another £20 on a carbon monoxide monitor.

that's what I'd do, and put the rest of the money towards other stuff.

[MichaelFinnigan]

No idea if we have microbore pipes. How would I tell? We do have a carbon monoxide alarm

I think we what we did was a DIY flush, drained the system, put some stuff in the tank

[specialsubject]

microbore pipes are about 8mm. How big are the pipes into and out of your radiators?

you could also spend £100-odd on a magnetic filter to get more gunge out of the system. You will certainly want one of these with a new boiler.

[MichaelFinnigan]

They're 15mm across. Does the 8mm refer to radius?

[specialsubject]

internal, I think - fairly easy to spot as they are very thin and look far too thin for the job.

laws of physics mean that power flush doesn't work on them. But it sounds like you don't have microbore.

we were also told that powerflush may not be a good idea if an old boiler is remaining in the system.