TRV system and prog thermostat

[Velvet]

So, new house, it has TRV's which I've never had before. I used to have non-TRV and fitted a prog thermostat which worked well, and since I was renting, I reinstated the old one and took the prog with me.

However, I'm a bit unsure as to where to site it (there's currently no roomstat at all on this setup, bypass rad is the bathroom upstairs).

I know if you put it in the same room/too close to a TRV the whole thing goes a bit wibbly, but I'm sort of limited in placement here. Ideally closeish to the boiler to avoid huge runs of cable woudl be good.

Is doing this going to run foul of the Part P regs?

Boiler is in utility room off kitchen (there's a door between kitchen and utility room, no water in utility except plumbed-in washing machine). Boiler is a combi, and apparently can have a roomstat fitted (currently just has 24/hour timer integrated with boiler).

Kitchen goes through to livingroom - working fireplace in there, along with TRV rad. Kitchen's clearly not ideal, due to heat fluctuations whilst cooking. Livingroom seems similar due to fireplace (not used every day, but if it is, can see it stopping heat to rest of house cos the stat will be off). Hallway/stairs is miniscule, and again, big temp shifts as door opened/shut. Upstairs landing might be feasible, but works out quite a way from the boiler. Bathroom's above the utility room... and the rest are bedrooms.

I'm half-minded to put it in the side hall (off kitchen, door to external, not d/glazed, no rad, off that is downstairs WC, no rad (though may add one in future) - but the door to the kitchen is left open to get heat to that area, in absence of rad.

Basically, just how close to a TRV rad would a roomstat have to be to completely bugger it all up? are we talking right next to it, opposite, far side of a 12'x12' room?

Any help appreciated greatly - 24 hour timer is pants and I can see it's going to waste loads of gas (and thus money) that I can ill afford.

Velvet

[Christian McArdle]

Or you can use an RF one.

Probably not. I'm not quite sure.

I prefer to use the living room, as it means that this room is the most accurately controlled. However, this should not be done if this room has auxilliary heating (i.e. your fireplace). Also, you may need to artificially throttle back this room a little when balancing, so it is the last room to heat up.

It could be totally adjacent. You just replace the TRV with a lockshield, or just turn the TRV to max, which has the same approximate effect.

Generally hallways are chosen when the living room has an additional heat appliance. In my case, I'm subzoned. The living room prog stat affects the front room and hallway as well. I have a bedroom zone and a kitchen zone. I will have a loft conversion zone and a conservatory zone in the future.

Christian.

[Velvet]

I didn't want to remove another TRV and replace with lockshield, to be honest, because I already have a bypass in the bathroom - though i suppose it wouldn't necessarily affect that, and would just act as a bigger bypass (add them together)?

Maybe the solution is to fit the extra rad in the downstairs WC - though not planning doing that till spring, on account of it being a DIY, me never having DIY'd plumbing before, and the entire system being drained down to do that, sort out a TRV on the wrong side of a rad - noisy; and I have a combi, so no HW while the system's drained down, which could be for several days depending how I get on with learning while I go!

I could then put the stat in the hallway adjacent to it. The door to outside isn't opened all that often, compared to the front or back door. And it'd make it a lot more convenient for the wiring - it's a matter of drilling a hole through two internal walls and running it in surface mounted trunking (unplastered brick walls).

Am I right in thinking that if I opened a TRV to max, it wouldn't switch off - and that I could balance the system by the lockshield on it, and it would then be acting as a non-TRV rad? I'm thinking that might be an easier way to go about this, in the event I decide to revert to non-progstat operation if it doesn't work out - I could just disable the stat, and re-balance and bring the TRV back into operation again?

[Richard Conway]

You could remove the head from the TRV so that nobody turns the rad off by accident - will ensure that it stays on constantly too.

[Christian McArdle]

Basically, yes. It will switch off about 30C. That would only happen if your programmable thermostat is broken.

Christian.

[Velvet]

S'only me, and i'm not likely to turn it off :-) Last place, had normal valves on both ends of hte rad, no lockshields. I balanced it all, 13 years later still hadn't been fiddled with :-)

Aaaah, the joy of not having fiddling kids :-)

[Velvet]

That might be a good interim solution to it if I do put the heaterstat in that hall and the kitchen TRV interferes (thus saving me draining the system down, and leaving adding the wc rad till spring) - sinc ethe kitchen TRV is the one on the wrong way roudn that shudders as it closes... keeping it on full would solve that problem, though obviously I'd still have to manually compensate for cooking affecting the operation of the roomstat, being in the hall should see it being far enough away to nto be too badly affected.

I think I see light at the end of the tunnel, and a way to fit the roomstat and leave me being able to easily revert to the pre-installedstat setup if it does c*ck it all up :-)

Cheers, UK-DIY, ever useful!