Radiator making a water flow noise when on

[Firemonkey]

Hi everyone, Ive had a dig around the internet but couldnt find a definate answer to a problem I'm having.

My central heating system is using a Vaillant EcoTec 28 combi boiler, normal radiators with Salus TRV310A TRV's fitted, the lounge radiator and the towel rad do not have the TRV's, the lounge has the wireless stat in it. (Hope thats enough info on my system, let me know if need to know more)

The radiator in the back bedroom is making a gushing noise when on setting 3 - 5 (basically on), its most noisy around the TRV.

I have bled the radiator several times with no luck, and have even drained it down and swapped with one from the other room and its still the same.

Only the one radiator makes this noise, and swapping it around made to difference at all - so that leads me onto thinking it could be a dodgy TRV.

Any ideas on what is causing this, or am I right in thinking I need to put a new TRV on ?

Thanks 🙂

 

[dontknowitall]

Presuming you closed the lockshield and opened it again when you changed the radiator I suppose it's worth changing the TRV.

 

[Firemonkey]

Yes, I closed the lockshield and made sure I reopened it again afterwards.

I'm going to order up a TRV, even if dont need it, its always good to have a spare.

Is there any particular order to refilling the rads. ie. should I open the lockshield before or after opening the TRV to full?

 

[dontknowitall]

No order, except to empty radiator of water before you remove it, unless you like swimming ...

 

[Firemonkey]

Swimming is good but not in rad water full of fernox 🙂

 

[tamz]

The noise is the increase in velocity of the water as the valve closes. Think of it as squeezing the end of a hose. Changing the valve may help but i doubt it.
If you have an Ecotec plus you could change the pump parameters but this may affect the rest of the system.

 

[Firemonkey]

The noise is the increase in velocity of the water as the valve closes.. .

If all the valves are open, I would have thought it wouldnt have a increase in velocity - I'll try a new TRV first, dont really want to mess with the boiler settings as its just the one radiator with issues

 

[tamz]

It is what it is. Believe me or don't. I don't need to listen to it so it don't bother me :wink:

 

[mickie]

take the top off the trv, see if it stops, if it doesnt it probably is the trv, if it does i guess its too hot in the room and the trv is doing its job

 

[Firemonkey]

I'll give it a go, it starts making the noise soon after I get the boiler to come on even if the room is cool

 

[mickie]

take the top off and push the pin in and out a few times, might unjam it

 

[doitmyself]

Have the rads been balanced?

 

[Firemonkey]

I dont know. I think this one rad is either the first or last one on the system as its directly above the boiler if that helps.


I tried turning the valves down on this rad and the others and doesnt make any difference.

 

[doitmyself]

If you have an Ecotec plus you could change the pump parameters but this may affect the rest of the system.

The OP said it was an Ecotec 28 which is a 'pro' version. That version only has a single stage pump.

The problem could be due to an incorrectly adjusted by-pass valve in the boiler.

Remove all TRV heads
Check the pins will go down and spring up (a little WD40 or silicon lubricant may help).
If the noise still continues, adjust the by-pass to a lower setting (see 5.8 in Installation Manual) until the noise stops.

If you are not sure that the rads have been balanced, you can read how to do it in How to balance a CH system.

 

[Firemonkey]

Thanks for the tips, I took all the TRV heads off of checked the pins a few times and didnt make any difference.

I also tried adjusing the by-pass and it made no difference either, but I was unsure as to how much to turn it so only did it a small amount (about 1/2 a turn to the left and did 1/2 a turn to the right)

Will have a go at balancing the system tomorrow as it looks like it could take a bit of time.

The system has only been in for 3 or 4 months so suprised im having a problem so soon. I did have to drain a few rads out to paint behind them, could adding some more inhibitor help as there might not be much left in the system?

 

[REDSAW]

first one of the boiler, so its full water rate and heats up quickly?.
possible due to pipe or restriction in it as water races through.(possible that debris like solder swirling in the pipe joint)
turn the l/shield down and open to 1/4 turn, this could be the ballancing rad also.
if not, check for kinked pipes or tight angles within it.

 

[boblydon]

Try checking the direction of the trv first.....by that I mean check wether it is on the flow or return, a lot of new valves are bi directional, if your valve is one of these then it does not matter wether it is fitted on the flow or return.However if like the danfoss valves I always fit, you need to adjust the flow direction on the valve.Your valve will, or they normally do have an arrow on the body, which shows the flow direction.Personally I would just change it for a danfoss valve, then you could almost be certain your noise will cease...........good luck, keep us posted.Bob