Boiler is banging (or pipes around boiler)

Seregwethrin

Dtp1979 wrote: »

By any chance do you have motorised valves?

No, just a manual one turning off the rads and keeping only hot cyclinder heating.

Seregwethrin

Okay I have a good finding!
When I turned the lever for hot cyclinder-only heating the knocking sound is almost gone when boiler is at rest. I got a few but they were very rare and not as strong.

Does this still support issue could be the sludge build up in the system and in the heat exchanger?

TheChizler

Seregwethrin wrote: »

Yeah I tried lowering the pressure to 1.1 bar from 1.6 bar and the knocking/hammering sound didn't change.

Around 1 is fine, if it was 3 or 4 say you might have had a leaking valve letting in mains pressure, but looks like that's not your issue.

Dtp1979

Seregwethrin wrote: »

Okay I have a good finding!
When I turned the lever for hot cyclinder-only heating the knocking sound is almost gone when boiler is at rest. I got a few but they were very rare and not as strong.

Does this still support issue could be the sludge build up in the system and in the heat exchanger?

I’m not following you. Does the lever turn off the radiators or not?

Seregwethrin

Dtp1979 wrote: »

I’m not following you. Does the lever turn off the radiators or not?

Attaching the photo below. When I move that lever I am pointing, only the hot cyclinder heats and I got less knocks, almost gone.
I believe it stops the hot water going towards the radiators.

Also I tested while all system is heating with radiators, I closed a bit that red balancing valve at the mid-bottom and that also seemed to reduce the knocks. I believe it is open now 3/4 of a full turn only. But when it is closed this tight and when I move the lever to hot cyclinder only mode the system was making weird noises like someone emptied a bucket of water to ground, like lashing rain for a few seconds then later again.

I find this very strange and I am still curious if there is a sludge build up somewhere... Though the 2 radiators I cleaned were quite dirty, if the pipes are similar, definitely the system needs looking after. The house is 25 years old and was rented in the last 10 years, so I don't think it was looked after well.

Dtp1979

I don’t see any lever. But either way, it’s sludge. No easy fix I’m afraid. The best you could do is dose your system with MC5 and let it circulate for 2-3 weeks and then have a professional powerflush the system

Seregwethrin

Dtp1979 wrote: »

I don’t see any lever. But either way, it’s sludge. No easy fix I’m afraid. The best you could do is dose your system with MC5 and let it circulate for 2-3 weeks and then have a professional powerflush the system

Sorry I called it lever, just that yellow valve there I'm pointing.

I will try keep calling around to have it cleaned... I am pretty sure it's not cleaned over 10+ years if not more.

Thank you

Dtp1979

Seregwethrin wrote: »

Sorry I called it lever, just that yellow valve there I'm pointing.

I will try keep calling around to have it cleaned... I am pretty sure it's not cleaned over 10+ years if not more.

Thank you

I’ve seen systems 3 years old filthy. And systems 40 years spotless.
Try the mc5. Preferably 2 bottles but make sure your plumber knows this. Book them in for mid January

Seregwethrin

I am just back to searching for another person. Thank you for all the help. I will post back about the result.

Seregwethrin

So I poured in Sentinel X400 to clean the sludge. Will keep it for 3 weeks after 2 hour full run then drain the system 3 times.

Here is the sludge came out from the bathroom rad. 2-3 times of what you see there, kept coming out.
Do you think this is normal levels of dirt? Is running X400 for 3 weeks too long?



This is how I poured in by using the filling kit from B&Q.