are trv's necessary?

[bludger]

Hi,

I remember reading somewhere that radiator thermostatic valves require the boiler to be on continually to able to respond to the individual valves. This could cost as much as the valves save.

Is this feasible? If it is, would a properly sited wall thermostat, and no trvs, do the job well?

 

[kirkgas]

apologies if im reading your post wrongly,
a TRV is to cool a room down, NOT to heat it up if that makes sense, if you have the main circuit set to 21 to suit the bathroom you use the other TRV's to cool the rooms down from the core circuit for comfort and economy so i dont really see why you need te boiler on 24/7, you only turn the boiler on when you want heat in one/several rooms, if no heat is required the boiler is off and if you require some heat in some rooms you close the unwanted TRV's

 

[mysteryman]

You should have a room thermostat as well, in a room where there is not a TRV on the radiator. This is usually the hall.

Better still, as the above post says, fit weather compensated control.

 

[holty]

so the OP might have an old mexico floor stander etc. how you gonna wc one of those

 

[ALEC1]

well technically you can but I wouldn't bother..the only place for an ideal mexico is in the skip in my opinion!

 

[bludger]

Interesting! Would you mind amplifying a little on the controllers you both mention? (Or post a link to this info).

Would I need just one controller for a seven rad system? If they are weather controlled would there have to be a external sensor?

Thanks for your replies

 

[holty]

firstly what boiler do you have and what setup. e.g s plan y plan combi?

 

[Charnwood]

TRVs coupled with an inteligent, programmable room stat is my choice.

 

[bludger]

Holty,

I'm trying to plan a revamp of a 10-11 year old heating system in a 3 bed detached house. I'm coming round to the idea that a new boiler and new double radiators (instead of large singles), plus good efficient controls would be much better than what is there now.

A weather controlled, heat only condensing boiler, is slowly occupying my mind.

It's a house I've just only bought so I can't be precise as yet but I'm going up there tonight and will take room measurements, existing rad sizes and anything else I can think of.

I don't want to make the obvious mistakes like putting a new clean boiler in a dirty system. My idea is to have things done right, by the right installer, giving a system which will function well and as economically as possible for years.

We will eventually downsize to this new little house when I can't cope with our present place. In the meantime we'll probably let the house out.

Sorry I can't be more specific today. I'm just trying to understand what is involved at the moment - hence my first post about TRVs.

 

[dormermike]

well technically you can but I wouldn't bother..the only place for an ideal mexico is in the skip in my opinion!

Oi! Whats wrong with an ideal mexico? I have one, bet it will out-last any new boiler I could fit. 36kw heats my house well too.

 

[ALEC1]

Yes but at what price to your pocket??? 30% of you gas bill is contributing to global warming..


Properly installed with compensation controls condensing boilers will do the service... The problem is manufacturers only have to provide spares for around 5 years...

 

[dormermike]

Yes but at what price to your pocket??? 30% of you gas bill is contributing to global warming..


Properly installed with compensation controls condensing boilers will do the service... The problem is manufacturers only have to provide spares for around 5 years...

Annual gas spend is approx. £1400 x 30% = £420. At a 2k installation cost (verrry optimistic!) thats five year break-even, before gas savings, so about 3 years before gas savings but not including heart-ache during install, breakdowns, increased annual servicing costs, etc.

Not worth it IMO, i should easily get another 5 years out of this boiler! Better to spend the money on better insulation, controls etc. A thermostat saved me 30% on consumption. Zoning will improve further. Then i'll add solar thermo.

And this sums it all up - thanks:

The problem is manufacturers only have to provide spares for around 5 years...

 

[JohnD]

I remember reading somewhere that radiator thermostatic valves require the boiler to be on continually to able to respond to the individual valves. This could cost as much as the valves save.

What a load of rubbish. That could only happen if fitted by some idiot who didn't fit a room stat, so the boiler was still trying to run even though the house is warm.

 

[bludger]

JohnD,

I searched again and found that I got the TRV information from www.miketheboilerman.com. He has a heading entitled Thermostatic Valves.

Me, I know little about central heating. I'm just searching around for information that will help me understand what I need and what the installer will be talking about.

It's a very complicated subject, ain't it?

 

[mysteryman]

To Bludger,

Fit a ******* boiler with weather compensation and TRVs on all rads except in the hall or bathroom. That will be an excellent job.

Just ignore those who can't be helpful.