TRV - thermostatic radiator valve

knipex

items wrote: »

I have my suspicions over TRV's due to their location, TRV's are fitted at pretty much a cold area, bottom area of rad is where cold air is drawn / pushed to rad, as rads heat by convection, cold at bottom hot out top. Many people brought this up with TRV manufacturer and to get over it, some TRV's are supplied with extra option of a movable sensor, its just a small box, box reads room temp and sends information back to needle control at rad valve through a metal type cable. The box is still fitted in a suspicious area as the cable is not long enough to locate at ideal area.

Fitting a house with TRV on all rads can be expensive compared to very little if not any benefit gained. I would sooner use cost of TRV to go towards fitting more room stats and breaking system down into more zones.

If heart set on TRV's have them fitted to flow pipe, most TRV's can be fitted on either flow or return but I find when TRV's are fitted on returns, balancing system can sometimes be a nightmare as no control over restriction part of balancing.

I find best energy efficient results is to break heating system into zones, living /dining areas, sleeping areas, kitchen / utility areas, halls and landings etc. Each zone is controlled by room stat fitted in a proper area, away from windows and doors, stats controlling motorized valves, as room reaches set temp stats will shut off motorized valves, when room temp drops stat calls for more heat, motorized valve opens. This way I know heating to rad is coming on or off depending on room temp. With TRV's I've no idea whats happening, slightest thing like a curtain can throw a TRV off, thats if they even work at all.

When you buy a TRV you'll notice written on box, TRV may turn rad off when room temp matches TRV setting, In all my days working on heating systems, I've never once found a rad with TRV fitted being off while room was roasting, cant even remember finding a rad with TRV fitted being a different temp (cooler) than any of the other rads in same house fitted with TRV's.

I've always wanted to take some readings of rads fitted with a heat sensor and try to work out if they do actually work but its almost impossible, instead of wasting time trying to figure out if they do work, I just dont use them. Each to their own I guess.

About the by pass, just leave one rad without TRV, smallest one like bathroom even en suite if fitted.

While I agree with you that zoning would be a better solution that is not feasible when retrofitting an older house.

I have a early 70's bungalow with one loop around the entire house. At the moments rads are either on or off so what we end up doing is rooms we rarely use (spare bedroom, etc) we turn off the rads completely which is not a great idea.

In my situation the only solution I can find is TRV's with remote sensors (2 meter cable)

looksee

Twiggy69 wrote: »

Yep, I've to replace the originals Myson's I fitted in 1993. They have been fine, but as we had the heating turned off over the summer, when we fired up the boiler, it only heats every other rad ,i.e. one hot,one cold, one hot, one cold etc

I had a plumber call in who recommended replacing 4 TRV's. To-night he arrived back and recommend I change my internal kerosene boiler for an external model - ballpark €4,500 !!!

Before I take this plunge, I intend to replace the 4 TRV's, flush out the system & see how the system operates. If that fails, I'll sell my soul for the new boiler!!!

Even before I take on with replacing the TRV's I would be interested in hearing about reviving faulty TRV's. Any links would be much apprecaited.

Regards,

T

We just got that job done - I'm still painting and clearing up! - we got the house completely repiped, a new boiler outside, new insulated hot water tank, three zone thermostats, 7 of the rads replaced, insulation and raised platform in the attic, all floors lifted and replaced, and a BER (which brought us from a D2to a C1, which is very good for a 40 year old house) plus a project manager, for about €6,600, of which we will get over a thousand back from seai. The job went like clockwork and was very well done.