Noisy Central Heating

[KennyPowers]

Hi,

After having the heating on for about an hour, I've noticed a 'scraping' in the pipes/rads. It goes after 5 minutes then comes back again later.

I've bled the rads, they seem ok. It could be the pipes expanding, unfortunately no easy way for me to get to them under the flooring.

I tried changing the pump from III to II, but that made it worse.

I did look online and saw a Fernox F2 Silencer that got good reviews, and I guess would be wasy to just dump in F&E tank. But I'm hesitant on dropping £20 on something that might not do anything.

Any ideas?

Cheers,
KP

 

[REEMS]

Does it sound like scrapping or could it be the sound of the pump passing air through it it when does it happen first thing or heating on for a while.

 

[REEMS]

Sorry just saw the on for an hour.

 

[KennyPowers]

Its difficult to locate where the noise is coming from (as the noise travels quite well along the pipes) however it appears to be coming from the pipes directly above the boiler in the kitchen. It sounds like a scraping/clanging noise.

 

[REEMS]

Is it an old boiler and where is the pump

 

[KennyPowers]

Boiler is a Potterton Prima F in the kitchen downstairs. Probably quite old, maybe original when house was built mid 90s? I don't know.

The pump is in upstairs airing cupboard next to cylinder.

Cheers,
KP

 

[REEMS]

You may have to try the cheapest option with maybe a clean out with fernox what happens when you put the pump on one the bearings in my pump failed and changed noise with different temps.

 

[KennyPowers]

So you think maybe a flush through rather than just dumping Fernox in the F&E and letting it mix in?

I've never drained a system before, but doesn't look too bad a job.

I seem to have different drain down valves that what I have seen elsewhere. With these do you just stick an old hose on the bottom bit, and open the top bit with a radiator bleed key?

 

[dilalio]

Those can be used to drain down, but they’re meant to be for just draining the rad. Have a hunt round for one on the pipes (look outside too).

 

[KennyPowers]

Only others I could find downstairs were two under the kitchen sink for the hot and cold taps, and this one on top of the boiler (excuse the dirty boiler top!)

I would have thought the valve would need to be lower than the rads though?

 

[dilalio]

It’s ok... use the one on the rad but you’ll need to leave rad valve open and also, as it’s small bore, it might get blocked during draining as sediment gets funnelled towards it. Also note that any other rads you have on drops downstairs will not drain unless they also have draincocks on them, which you would need to drain those from.