Thermostatic Radiator Valves

[Gram43]

Here's a question for all you good plumbing and heating guru's:-

We had a complete new heating system installed in our home last year and the very old boiler and hot water tank was removed. We have a nice condensing combi boiler now, which gives us hot water when needed and great heating and means we're not heating a tank of water for nothing. Our fuel type is LPG, as this was installed in the house when we bought it, so we continued with the contract, as its the cheapest fuel we've found.

We also have great new hi output rads with TRV's and a new thermostatic control in the hallway. Now here's my query:-

Which is the best way to set up this system to give us the heat when we want it and also maintain good fuel consumption. I seem to be constantly changing the TRV settings per room (once the heating has been on an hour or so, so all the rooms are already warm), plus I've been altering the thermo control in the hall, but then there's also the thermo control on the boiler.

There's probably no definitive way to set the system up, but has anyone got any guidelines as to which controls to set to what, to enable the efficiency of the system and maintain good fuel consumption.

We asked the engineer who installed it to come over the other day to test the boiler and all was completely OK. Reason we asked is that we have gone through a tank of fuel in 1.5 months and we were lead to believe the system would be more efficient that the old one. but it appears not to be!!

Cheers..........Graham

[MuscleBob.Buffpants]

Do you have a TRV on the radiator in the hall?

If so, that may be your problem - our plumber told us that you shouldn't have a TRV on a radiator in the same room as the thermostat.

[Gram43]

Originally Posted by MuscleBob.Buffpants

Do you have a TRV on the radiator in the hall?

If so, that may be your problem - our plumber told us that you shouldn't have a TRV on a radiator in the same room as the thermostat.

Hi, yes there is, I know that if the thermo control is in the same area then it'll probably trigger the house temp to shut off earlier than it should. So, the hall rad is turned lower than the other rooms.

[angleseydiver]

Hi Graham,
the TRVs have big knobs on them that are easy to fiddle with but that doesn't mean they're meant to be fiddled with
You should have been given a leaflet with basic instructions on how they work and how to use them. Normally they have numbers on 1-5 Where 5= toasty-warm, 4 = cosy-warm, 3= warm, 2= ok-ish and 1= takes the chill off. there is also usually a *= minimum frost protection and a 0= off. Most people have lounge rad at 4 or 5, dining room/ kitchen 3 or 4 , bedrooms 2-3 and any "spare rooms on *or 1. Bathrooms tend to have plain valves and towel-rails.TRVs work by sensing the temp of the room and shut the supply to the rad when room is up to selected temp and open the supply when the temp drops. They shouldn't be fitted in positions where they are affected by draughts or sunlight or where they may get covered by curtains etc. If you have a roaring fire in the lounge the radiator will stay cold- it,s not broken it just doesn't need to be on because the room is warm - saves you money (in theory)
The room stat on the wall is to comply with current regs, most have it set around 20, it's function is to sense the temp of the house generally and shuts the supply to all the rads at once when it's satisfied- it's also handy for knocking the heating on and off and the programmer is on the boiler in the garage,.
Anyway, having played with the system for a week or so you should find settings you're happy with (Many TRVs are lockable within your personal range to stop kids/wives from turning them all to full-blast or off)
Obviously, the lower you set all these stats the less fuel you use.
Oh, the boiler stat- this controls the temp of the hot water flowing through the system- if it's off most of the day and set to come on just before you get back from work it wants setting fairly high to give a rapid response, if it's normally on all day you can turn it down to around half, generally.
HTH,
Terry

[Gram43]

Many thanks Terry for all your advice here.
I'm almost there with what you have said, but will certainly take on board the settings etc.

When the system was replaced we were seriously grateful to have the house warm within 15 minutes, instead of nearly 3 hours waiting. Plus, we have just 1 mains fed shower now and wifey uses this every morning, whilst I prefer a bath, but hot water exactly when you need it is brill. However, our engineer decided to tell us that mains fed showers use a lot of fuel/boiler power to get them going!! Should've mentioned this at the start if true.

I appreciate that this is all trial and error so I guess a lot of fiddliing with is required. On the other hand, we never had a fill up of fuel from April 2007 to December 2007, so I guess we can't complain too much eh?

Thanks again.............Graham

Originally Posted by angleseydiver

Hi Graham,
the TRVs have big knobs on them that are easy to fiddle with but that doesn't mean they're meant to be fiddled with
You should have been given a leaflet with basic instructions on how they work and how to use them. Normally they have numbers on 1-5 Where 5= toasty-warm, 4 = cosy-warm, 3= warm, 2= ok-ish and 1= takes the chill off. there is also usually a *= minimum frost protection and a 0= off. Most people have lounge rad at 4 or 5, dining room/ kitchen 3 or 4 , bedrooms 2-3 and any "spare rooms on *or 1. Bathrooms tend to have plain valves and towel-rails.TRVs work by sensing the temp of the room and shut the supply to the rad when room is up to selected temp and open the supply when the temp drops. They shouldn't be fitted in positions where they are affected by draughts or sunlight or where they may get covered by curtains etc. If you have a roaring fire in the lounge the radiator will stay cold- it,s not broken it just doesn't need to be on because the room is warm - saves you money (in theory)
The room stat on the wall is to comply with current regs, most have it set around 20, it's function is to sense the temp of the house generally and shuts the supply to all the rads at once when it's satisfied- it's also handy for knocking the heating on and off and the programmer is on the boiler in the garage,.
Anyway, having played with the system for a week or so you should find settings you're happy with (Many TRVs are lockable within your personal range to stop kids/wives from turning them all to full-blast or off)
Obviously, the lower you set all these stats the less fuel you use.
Oh, the boiler stat- this controls the temp of the hot water flowing through the system- if it's off most of the day and set to come on just before you get back from work it wants setting fairly high to give a rapid response, if it's normally on all day you can turn it down to around half, generally.
HTH,
Terry

[colinicky]

Originally Posted by Gram43

On the other hand, we never had a fill up of fuel from April 2007 to December 2007, so I guess we can't complain too much eh?

Thanks again.............Graham

How big is the tank ? (lts)

We went through £600 last year but this includes cooking as well . Also we live in a 4 bedroom mobile home ie thin 2 inch wooden walls & wooden floors with very little insulation !

[Gram43]

Its about 1000/1100 lts, most fills we have had have been just under the 1000lts. They never fill them completely as they allow for expansion etc.

We also cook with the stuff, however, as there's only 2 of us, we don't use the hob everyday, but we know that this will contribute to usage. On our previous system, we never had a gas hob.

As I mentioned, it's all trial and error I guess. I've just read the tank and we're just going off 1/4 mark.

We have a large 'T' shaped bungalow, all fully double glazed and I re-laid all the loft insulation and boarded the central section of the loft later last year, so apart from cavity wall insulation, we're sorted!

[Spacehopper]

It sounds as if your heating system may need balancing. It's a job the installer should have done but possibly didn't. Have a look at this link for a fairly simple procedure. You need to have all your thermostatic valves fully open when you do this. The valve you adjust (lock shield valve or LSV) is on the other end of the rad to the thermostatic valve (control valve).

It's a time consuming task but should result in a good system. Don't forget to record the starting position of all the valves - just in case

Terry is right, once the TRVs have been set they shouldn't need adjusting, but they may get moved for all sorts of reasons. A favourite in our house is for 'er indoors to turn them up to dry the washing quicker and then forget to reset them.

Good luck

Gareth

[colinicky]

Originally Posted by Gram43

We also cook with the stuff, however, as there's only 2 of us, we don't use the hob everyday, but we know that this will contribute to usage. On our previous system, we never had a gas hob.

To give you an idea for cooking purposes we had 47kg propane cylinders for the cooking & with 3 of us SWMBO,Me & daughter using hob & grill/oven every day we used to go through 1 cylinder in 10 months . bear in mind that a 47kg cylinder has approx 100lts of gas in it .

[Gram43]

Originally Posted by colinicky

To give you an idea for cooking purposes we had 47kg propane cylinders for the cooking & with 3 of us SWMBO,Me & daughter using hob & grill/oven every day we used to go through 1 cylinder in 10 months . bear in mind that a 47kg cylinder has approx 100lts of gas in it .

We had a static caravan on a site (used as a holiday home) before we moved up here and we had an oven, hob and fire that were fuelled by one propane bottle(the tall domestic ones), this used to last us 18 months. During the summer for some cooking, but in the winter for everything obviously.

We've just had the tank filled this morning and it took 968lts, same as last fill, so we've used this amount since December 05th, nearly 2 months.

As for bleeding the system, I don't think there's any air in it and all seems to work well, so we'll just have to have a play with the settings to get an optimum level.