Rattling pipework and radiators

[Steeevo]

Hi. I have had this noise for 5 years and have had a plumber check it out and he said it could be a bit of solder in a pipe thats rattling and is impossible to find. I gave up getting the noise fixed and have lived with it.
A quick run down of what happens is when the thermostat kicks in and starts to heat the radiators the rattling noise starts straight away and doesnt stop until the thermostat gets upto temperature.

Videos of the noise
View: https://youtu.be/J289VwXi4F0

View: https://youtu.be/pE_wkSsGHN8


I have a recirculating pump with a switch 1, 2 and 3. On 1 it makes hardly any noise on 2 it gets loud and on 3 the rattling is very loud.

i can hear the rattling in most of my radiators but is loudest upstairs near the pump and in 2 rooms upstairs.

sounds like loads of ball bearings. Any experts with some invaluable experience would be greatly appreciated.

 

[Stigster]

I'd suspect a faulty pump. The noise transfer through water and pipework can travel a long way so I'm not surprised you can hear it at the radiators when it's running. Have you had the pump out to have a look at it, see if it's clogged with debris or maybe has a cracked impeller causing imbalance and vibration? The bearings could have failed too.

The way the noise ramps up in direct association with an increase in pump speed leads me to think the problem lies within the pump.

 

[Darren Jackson]

I agree with the #Stigster above. Most likely the pump. Put a long screwdriver or wooden spoon onto the pump and then to your ear and listen to the rattle; if it sound really loud and you can feel the vibrations then its time for a new pump or pump head. Do the same with the rads and listen on if it is louder at the pump or the rads. If you have not got one already then get a mag filter installed. Make sure it is one that will also catch non magnetic debris such as a Magna-Clean.

 

[Steeevo]

Thanks for your help. Does this pump also work with the hot water system.
When the hot water kicks in that pump starts aswell but doesnt make the rattling noise, Only when the rads come on does the pump/pipework sound rattly

 

[Stigster]

Thanks for your help. Does this pump also work with the hot water system.
When the hot water kicks in that pump starts aswell but doesnt make the rattling noise, Only when the rads come on does the pump/pipework sound rattly

Initially I thought that now eliminated the pump as the problem but on further thought it could still be that.

The pump is there to push water around both the central heating circuits and hot water cylinder primaries. I suspect that there are going to be different flow velocities across the two different circuits. In one operating mode the rattle shows and in the other with a different velocity the rattle is not produced.

My money is still on the pump, mostly because I've never heard that type of noise being caused by radiators/TRVs but that doesn't mean it doesn't happen. I suppose it really could be a ball of solder in a rad near the pump making the noise.

I would try to eliminate the radiator valves from the equation by shutting them all down and running the system for a couple of minutes, see if the noise is still present. If the noise persists with the radiator valves screwed closed then I'm still thinking the fault is at the pump.

On the lockshield side, count the number of turns to close the valve and note that for each radiator. If the system was properly balanced when it was set up, you'll want to put the lockshield valves open to the same point after your test. Give that a go and report back. It's going to be a process of elimination.

 

[Ricky]

an other cause is an old fashioned trv on the wrong end,
the solder could be in the heating pipe work so only rattles when the heating is on
[automerge]1575629784[/automerge]

an other cause is an old fashioned trv on the wrong end,
the solder could be in the heating pipe work so only rattles when the heating is on

looking at your video it looks like an older trv with only one arrow on it so it has to be on the flow

 

[Steeevo]

Ok. Thanks for your advice. Im going to get the pump changed first and try that. So i need a plumber.

also now my hot water isnt coming on at the scheduled times. If its on and I run the hot tap on the bath for a few minutes it kicks in and starts heating the hot water though. Whats broken now????

 

[Steeevo]

Ok. Thanks for your advice. Im going to get the pump changed first and try that. So i need a plumber.

also now my hot water isnt coming on at the scheduled times. If its on and I run the hot tap on the bath for a few minutes it kicks in and starts heating the hot water though. Whats broken now????

Could it be the changeover valve?