Noisy Radiators.

[tony coleman]

Our combi boiler is 4 years old and serviced once a year. Over the last 4 months I've noticed the rads becoming noisier. They have a hissing/whoosing sound. If you turn the valve on them slightly it will stop but the rad wont then heat up. Anyone any ideas ? Cheers.

 

[RandomJ]

Bleed them.

 

[Blue Mist]

Bleed them.

To give the op a bit more info!!!! You should have a small key that goes into the side of the rad. If you don't they are cheap to buy. Turn the square lock and it will hiss, do this until water squirts out. Then close them off. This is bleeding the radiator. Basically getting rid of air. Turn the heating on and they should be warm. If your rads are old have a cloth to soak up the water as it could be dirty.

If that doesn't work, brick your windows, torch your house and you know the rest.

 

[LongsightM13]

Sounds like a punk band

 

[kaz7]

Kick them , then bleed them

 

[remember arthur mann]

To give the op a bit more info!!!! You should have a small key that goes into the side of the rad. If you don't they are cheap to buy. Turn the square lock and it will hiss, do this until water squirts out. Then close them off. This is bleeding the radiator. Basically getting rid of air. Turn the heating on and they should be warm. If your rads are old have a cloth to soak up the water as it could be dirty.

If that doesn't work, brick your windows, torch your house and you know the rest.

Not forgetting to re-pressurise said system.

 

[Citizen of Legoland]

Our combi boiler is 4 years old and serviced once a year. Over the last 4 months I've noticed the rads becoming noisier. They have a hissing/whoosing sound. If you turn the valve on them slightly it will stop but the rad wont then heat up. Anyone any ideas ? Cheers.

The valve you are turning is the thermostatic one, yes? Not the other side which you usually have a cap on that needs taking off then that valve needs an adjustable wrench to turn. If bleeding them as suggested doesn't work then you could try re-balancing the system.

How to Balance Radiators

If you’ve noticed some of the radiators in your home are cold while others are hot, use our easy to read step-by-step DIY guide on how to balance radiators to even out heat distribution

www.homebuilding.co.uk

After that you're looking at replacing valves or flushing out the system (which shouldn't be the case as it should have been done when the new boiler was installed).

 

[grunge]

Not forgetting to re-pressurise said system.

Bugger, didn't know about that, bled my radiators before winter and just checked the pressure, it was about as low as it could be without erroring out. could explain why our gas bill was so high over winter!!

Just re pressurised it now.

So for those in the know, what sort of level of efficiency drop off are we talking here? the needle was sitting on the very bottom of the green, possibly between green and the white area.

 

[Blue Mist]

Not forgetting to re-pressurise said system.

Yeh wot he said

 

[Citizen of Legoland]

Bugger, didn't know about that, bled my radiators before winter and just checked the pressure, it was about as low as it could be without erroring out. could explain why our gas bill was so high over winter!!

Just re pressurised it now.

So for those in the know, what sort of level of efficiency drop off are we talking here? the needle was sitting on the very bottom of the green, possibly between green and the white area.

It wil be okay at 1 bar but might have caused problems if running a lot at say 0.5 bar or below. The normal working pressure is 1.5bar but will depend on the model. What bar is the "bottom of the green"? There's usually a red danger zone below and above green.