TRV dont seem to turn off.......all of them?! ...thanks for the sds posts too :)

[Colin]

Dear all,

I am having problems with all of the trv s on all my radiators. I have only recently moved in to this house, and i have no knowledge of how long they have been fitted, nor do i have the destructions.

I have been unable to test them when the house has been above 16 / 17 degrees (ish) i understood from my parents house that if you have them screwed right in, they will turn a radiator off at about 10 degress c. Is this generally the case? Would heating them up with a hair dryer or similar work?.....see if that would turn them off?? Or any other ideas?

Also, how do they work! Anyone know?!

Aside from this, can i thank every one for their advice and posts on SDS. I just ordered a Makita hr2450. I cant wait to start my reighn of terror against my solid concrete walls that have driven my dads old black and decker to an early grave!.

[Tim S]

They will have some minimum temperature that they *can* be set down to. Don't know if it follows any sort of standard or not (unlikely). Should be way below 16C and above 0C

Would heating them up with a hair dryer or

Yes - that's a good way. Will be hard to say exactly what temperature they triggered at, but it will show if they are working.

Borrow a couple of 2/3 kW electric heaters? Presumably your CH isn't a happy bunny at all if you can't get the place warm???

As most designs allow the TRV head to be removed from the valve body without touching the plumbed connections (and don't come running to me if you flood your house - have a look at them, it should be fairly clear how to remove the head, if it's desgned to come off dry, in service).

For a start, removing the head should allow the valve to open - so you can see if you have any stuck valves.

Then with the head removed, depending on the design, you could dunk it in a bowl of warm water with a thermometer and see how it's behaving - but it sounds like your problems are more general that that?

The ones I've seen (Drayton) have a metal head containing fluid of some sort which expands and pushes down on a pin in the valve part of the assembly, closing the valve.

Timbo

[Dave Plowman (News)]

Remove the top part - there's a metal ring just below the plastic, which should come undone by hand. That will reveal a pin which controls the water valve. It should move down with finger pressure against a spring and return. If it doesn't, they're stuck. They can sometimes be freed with a tap from a chunk of wood or similar. But if old might leak after this.

[Colin]

Thankyou for all responses. Having tryed the hair dryer thing; It seems that either ;

a. these valves were designed by someone with shares in powergen.....or b. i am too tightfisted and should leave the central heating for longer.

At a guess i would say that on their lowest setting, screwed right in, they turn off at about 14 maybe 15 degrees c. Which i guess i should be heating the house to about that anyway. I was just a bit confused that when screwed in, the radiator still functioned, i expected it to turn off.

As this is my first house / winter gas bill, i am unsure of how much CH 'on' time costs, so in case anyone was wondering, that is why i am maybe alittle over cautious with heating.Besides, I dont get cold with lots of jumpers :-)

As a bit of an offshoot from this topic, is there any information on the heat retaining properties of homes with (as mine) solid concrete walls as apposed to a 'cavitied' wall? Are concrete walls as bad as it gets? (aside from maybe.....copper or ice?)

Thankyou again,

Colin

[Dave Plowman (News)]

Most have a frost setting which is a deal less than 14-15C. This is the minium. To turn them off fully for temperatures below this, you re-install the cap that comes with them when new. This turns them off fully regardless. In theory.

[Hugo Nebula]

On Sat, 04 Dec 2004 22:39:21 GMT, a particular chimpanzee named "Colin" randomly hit the keyboard and produced:

It's unusual for a house to be built entirely of cast in-situ concrete, or even concrete panels. Is this what you mean, or do you mean concrete blocks?

Reinforced structural concrete by itself is a poor insulator (having a conductivity of 2.3W/m°C compared to 0.77W/m°C for brick), but isn't used over a whole wall, only to form a frame. There is usually some form of infill panels with internal or external insulation. There were other types of system builds (such as 'no-fines' concrete) which were used by Councils in the '60s and '70s. I would have thought most of these have been upgraded (or demolished) by now.

Most houses in the last 20 years have been built with concrete blocks of varying density to the inner leaf. The conductivity can vary from

1.13W/m°C (worse than brick) to 0.11W/m°C (better).

[Colin]

Sadly i think this is a house that has not been knocked down, or upgraded. It is according to the survey, a 1950s ish system build, and the concrete seems to be made up of pebbles some of which seem to be quartz in hardness! I think there is method that the council have used to insulate them by putting an outer layer of something clever on to the walls but i understand that unless it is being done on mass then the figure would probably come close to buying a new house.

Thankyou, Colin