I've got a radiator that is not warming up and I think the TRV is
stuck. I know this happens now and again. If you take the top off,
there is a pin. I can't remember, do I push it in or pull it out to
Would a little 3-in-1 or WD40 on it prevent this happening again?
Pull it out. Then check it's working by pushing it in and releasing it
a few times. The total movement is only a few millimetres.
Lubricant might help, but usually they are stuck internally due to
A good tip is to open all the TRVs full when the heating goes off for
the summer. The only problem is that other people go around closing
them thinking "We don't need the radiators on in this weather." This,
of course, is the converse of the present problem where they whack
them up full because "The radiator's gone cold."
I do wonder how much "carbon" could be saved by an advertising
campaign to tell people how to use TRVs properly.
The pin is pushed to shut off the water flow. So if it is stuck down
then it is off.
Pulling it may free it, or you may find it is a free floating pin not
actually attached to the valve mechanism in which case pulling it will
make no difference.
A few gentle taps with a small hammer on the side of the valve may free it.
> Would a little 3-in-1 or WD40 on it prevent this happening again? Probably not...
Or getting rid of the wretched things completely and using
sensibly-positioned thermostats and motorised valves of a size and
design that you wouldn't mind having them visible. I have used Sauter
AXT111 actuators, but they're so far off being a mainstream product that
they're too expensive for many purposes - and difficult to find with
Guess who's in the process of designing a heating system and wants it
fully zoned - 5 rooms - and adjustable to real, understood, temperature
values, and set without grovelling on the floor, trying to move a valve
between four-and-a-tiny-bit and four-and-a-tiny-bit-and-a-gnat's.
In article , Autolycus
You could do worse than to look at the multizone RF system offered by
Honeywell, sorry I don't have the numbers but it should be easy to find.
IIRC, set points are sent to RF radiator valves and the control is done
locally. I have no time for the RF fad but think that the only way that
multizone control will reach the mass market is that way as both new
build and retrofit would find multizone cabling too costly. The
Honeywell system claims proportional control and the intelligence to
shut down heat in a room that has a window open for ventilation if
My own system has a zone valve for each room but controls for such a
system have to be home grown and proportional control using off the
shelf components is just not an option.
500 quid for a kit to control 6 existing TRVs. but only provides 2 zones. If
you wanted totally independent zones for each room you could add up to 3
extra CM67z controllers at about 80 quid each, providing 2 more zones per
How many people (like SWMBO, to name but one) come into a cold house,
switch the heating on and crank up all the TRVs to max, rather than
leaving them set at 2-3 where they were previously set for a comfortable
operating temperature, because that way "they'll warm up quicker".
And then later - "bloody hell it's hot in here, I'll open the windows"
Tell me about it. I used to be married to someone who was brought up in a
communist country where there were no such things as gas meters and bills in
the "very attractive" high rise flats she lived in. Heating on full 24/7 and
using the window as a thermostat.
Bless her my arse.
In article , Lobster
Indeed, I have given up explaining the concept of thermostats and why
raising the setting does not result in an increase in comfort level, I
spend my time either slapping heads or installing tamperproof controls
Hmmmm. And you're still sensing room temperatures at the bottom corners
of radiators, unless, aiui, you have one CM67z per room.
So, for my system, I'd need:
an HC60NG receiver - £64
five HR80UK valve heads @ £67 - £335
five CM67 @ £60 - £300 (or would that have to be 4 plus
1 other of some sort?)
five trv bodies - say - £ 50
i.e. about £750.
Five programmable room stats @ £32 £160
Five motorised valves @ £22 £110
Five lockshields £ 10
a wiring centre £ 10
cable and fittings
i.e. about £325
Less sophisticated control, and it's more work wiring it all up, but
each item can be replaced if it fails by something functionally
identical from another maker, and it leaves £425 to spend on tools, or
If Tower can make a 22mm motorised valve and bes can sell it for £22,
surely it shouldn't be beyond the wit of man incorporate one in a
radiator valve for about the same price?
[snip - comparison of Honeywell CM Zone Wireless system against hardwired
I'm inclined to agree there. I looked at the CM Zone option as a less
disruptive way of applying zones to our existing system but dismissed it as
an expensive approach with some practical drawbacks. If we were starting
from scratch I'd go for zones with motorised valves but I don't fancy the
disruption so I expect we'll settle for a relatively cheap and cheerful
addition of a CM927 to the existing system which has TRVs throughout but no
I'm glad to see that it's not just my wife who does this.
I might as well replace the heating thermostat with one of those great big knife
switches out of a Frankenstein movie, because that's how she treats it.
In article ,
I suspect that maybe OTT.
I designed and installed central heating about 6 years ago.
I split into downstairs and upstairs zones with separate control.
I did accurate heatloss calculations for each room and sized the
rads appropriately. TRVs are fitted on all rads except in the two
rooms with thermostats, but I simply leave them fully open all
the time. With the radiators matching the heat loss from each
room, all rooms match each other temperature-wise, and when the
rooms with the stats are at the right temperature, so are all
the other rooms.
If I hadn't done accurate heat-loss calculations, then TRV's
would have been necessary to get desired temperatures, but with
proper heat-loss calcs and accurately sized rads, they aren't
doing anything. If I'd known how accurate my heat-loss calcs were,
I might not have bothered fitting the TRVs at the time. (However,
they or something equivalent are needed by Part L nowadays.)