Power flushing OFCH

Pepp1989

Bought a new house recently. 1970s 2 storey detached. As title says... it's oil fired central heating. The majority of the rads have cold spots mainly in the central lower half. Google tells me that it is likely sludge build up and that a power flush is the solution and that it would cost 400e ballpark.

I am clueless about this but just wondering

1. if this would actually help things.
2. Is 400e a reasonable price.

The boiler is operating at about 85% according to my survey. But there are no zones etc. But that's a job for another day.

Would be grateful for any advice from those more experienced. Thanks.

Wearb

You need to identify the cause of the sludge and remedy that. Then a power flush would be in order.

nordicb

If it is of any help. Perhaps depends on type of radiators installed. I had 25 yo flat panel ones, single and double. Had each of problematic rads removed and power flushed, turning them physically in all ways, etc, until clear water could be observed. But this did not get rid of cold spots in the bottom middle. Most of problematic ones were on the ground floor. While I did it myself, I'm not sure if it is as effective as I believed. One of them started leaking in the middle shortly after and I ended up replacing all rads and valves to equivalent ones from Stelrad and Termoteknik - some sizes were not available from Stelrad alone.

I'm sure there are plenty of other rad brands, but Stelrads were recommended from multiple sources.

funnyname

New efficient rads are very cheap, might be more cost effective replacing rads and boiler than trying to improve an outdated system.

Kirk Van Houten

We recently changed our boiler (20+ years old) and as we flushed the system a number of the rads leaked. Was told it was due to sludge etc corroding in spots.
Ended up replacing them all more for peace of mind and to save any insurance claims.
Made sure the new boiler had a filter fitted as well.
Also got the house zoned (upstairs, downstairs and water) and it's like moving from Aberdeen to the Algarve in terms of the difference in heat.

Pepp1989

Kirk Van Houten wrote:

We recently changed our boiler (20+ years old) and as we flushed the system a number of the rads leaked. Was told it was due to sludge etc corroding in spots. Ended up replacing them all more for peace of mind and to save any insurance claims. Made sure the new boiler had a filter fitted as well. Also got the house zoned (upstairs, downstairs and water) and it's like moving from Aberdeen to the Algarve in terms of the difference in heat.

This is very helpful thanks. Would mind pm-ing me a ball park cost for the works you had done? And how many rads you had changed? This is something I would be interested in having done but funds are tight atm having just moved in! But I hate false economy.

Wearb

There are many reasons for sludge, the most common is a leak that goes unnoticed because of automatic top up. This could be from an expansion tank in the roof or an automatic supply from mains.

You'll end up back where you started if you don't sort the cause.

Dtp1979

If rads leak during or after a powerflush then they were always going to leak. Powerflushing only exposes leak, it does not cause them.
The reason sludge builds up on systems can be a mystery sometimes.
In my area some estates seem to be prone to sludge. No leaks. It can be down to cheap inhibitors used at the start, or a mixture of metals in the system.

Man with broke phone

Replace the system now before you do up the house painting everything, putting down floors and stuff.

Pepp1989

Just to follow up on this. The plumber carried out a power flush and identified what he felt was the cause of the build up. He said the system was pitching and he said he thinks he has it resolved now.

Nice difference in heat from all the rads now.

Next job is replacing the boilers and looking at zones!

Thanks for the advice.