I recently had a new gas boiler installed (condensing, but not combi) and
the central heating converted to fully pumped but not pressurised.
Inhibiter was added to the system the next day after installation. I have
since had to bleed the bathroom radiator twice (not getting hot at the top)
and my lounge radiator at both ends (same problem). Is this normal after
installation? All radiators are original and the system has always
contained inhibitor.

The system now seems to be working fine and has a rapid warm-up time.
However, every time the boiler fires, I can hear a clicking noise from my
bedroom radiator, which varies in frequency from several times a second to
once every few seconds. This is most annoying as it wakes me up at 6
o'clock every morning. I've tried reducing the flow by turning down the
valve on the rad. and also setting the pump to 2 instead of 3, but all to no
avail. The only cure is to shut off the radiator completely, but then my
bedroom is cold in the morning.

None of the radiators are fitted with thermostatic valves and the problem
did not occur with the old boiler. I think that the problem may be due to
thermal expansion but is there anything I can do to eliminate this annoying
noise? All other rads are quiet.

Terry D.

Terry D wrote:
I recently had a new gas boiler installed (condensing, but not combi) and
the central heating converted to fully pumped but not pressurised.
Inhibiter was added to the system the next day after installation. I have
since had to bleed the bathroom radiator twice (not getting hot at the top)
and my lounge radiator at both ends (same problem). Is this normal after
installation? All radiators are original and the system has always
contained inhibitor.

It may take a week or two for all the air to be finally expelled if the
system has just been refilled. If you find you are still bleeding lots
of air after a couple of weeks then suspect a problem. It would also be
worth checking that the system is not pumping over, or sucking air in
via the vent pipe.

The system now seems to be working fine and has a rapid warm-up time.
However, every time the boiler fires, I can hear a clicking noise from my
bedroom radiator, which varies in frequency from several times a second to
once every few seconds. This is most annoying as it wakes me up at 6
o'clock every morning. I've tried reducing the flow by turning down the
valve on the rad. and also setting the pump to 2 instead of 3, but all to no
avail. The only cure is to shut off the radiator completely, but then my
bedroom is cold in the morning.

None of the radiators are fitted with thermostatic valves and the problem
did not occur with the old boiler. I think that the problem may be due to
thermal expansion but is there anything I can do to eliminate this annoying
noise? All other rads are quiet.

This is probably just a side effect of the rapid warm up. Check the rad
has the plastic spacers fitted between it and the wall brackets, and
that the tails and pipes leading to it are not rubbing against wood.
Small bits of old carpet can be placed round pipes as they cross joists
etc to reduce this sort of noise. If need be try replacing the rad with
a new one.

--
Cheers,

John.

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