Best way to set up gas central heating controls

[ss]

I am trying to get the best economies with an acceptable level of comfort, so a bit of a balancing act. Using a Baxi combi boiler with 14 radiators. (some rads turned off) (house occupied 24/7) In general terms I can take lower temps during the day but raise them at night which I have done via the time control/stat. Now as I can see there are 3 elements.

1. The temp controls at the boiler (low/med/high)for controlling the water and another for the rads.
2. The thermostat on the time control box.
3. TVR valves

Is there a `best way` to adjust anything eg is it better to have a lower temp setting at the boiler or a higher one and let the stat control the heat. As far as the TVR valves are concerned I have them mid point in bedrooms etc but full on in the main lounge (where the stat is) Short of getting uncomfortable is there a `best` set up for economy use in general terms accepting we all have different comfort levels.

[Andrew Gabriel]

If it's a condensing boiler, the most efficient position is to set the boiler temperature as low as you can, which still manages to keeps the rooms at correct temperature and never quite causes the room stat to click off.

The trouble with this is that you will have to adjust the boiler temperature depending on the outside temperature, turning it up a bit when it's colder outside, and down when it's warmer outside. Also have to turn it up whilst you are heating the house up from cold. This is what a weather compensation system does for you automatically.

A compromise which is not significantly worse than ideal would be to have the boiler just slightly hotter and have the room stat only occasionally click off, but would avoid you having to fiddle with the boiler temperature so often.

If it's not a condensing boiler, the same applies, but you need to be careful not to run the boiler too low that it starts condensing, as this will do a non-condensing boiler some serious damage. In theory, the boiler should protect itself against this by not running too low, but I don't know that all boilers do.

That sounds fine for the TRVs.

[Roger Mills]

You shouldn't really have a TRV at all in the room where the room stat is. That should be the slowest room to heat up so that the TRVs in the other rooms have all done their thing before the stat turns the boiler off. [May possibly not be the best place for the room stat].

[ss]

I`ll give that a go and see how it feels/costs as I am currently monitoring gas usage on a daily basis until I get a good compromise.

[Dave Liquorice]

The daily weather will have too much influence, it will tend to mask the effects of any changes you make to the settings. Much better to try settings for a week at a time and record the gas use per week, perhaps making a note about the weather for each week, temperature and wind mainly.

[Andy Champ]

Curious. We turn the heating off at night. I have no objection to STWNFI cuddling up :)

besides which we have a decent duvet, and rarely get cold in bed.

Andy

[ss]

I will move to a weekly reading but to get a feel for some of the changes I am making I have been monitoring on a daily basis for a couple of weeks and will for another week and then move to weekly. So far I have managed to save about 3 kWh per day. I know I can make some further improvements with draught proofing when I have time and the dog passes on! I have wooden laminate flooring and want to carpet but as the dog is on his last legs will wait til then before carpeting.

The house is 10 rooms including 2 toilets plus 2 small hallways and I am on target to reduce combined bills to approx £1000 per year.....getting there :-)

[ss]

By night I mean from say 6pm -10.30pm :-) Then it is set to 9C for overnight when the duvet and wife take over.

[meow2222]

You'll get far more payback by putting your time/effort into draughtproofing and insulating

NT

[Andrew Gabriel]

I'm less that that here (detached, 7 rooms), but I don't any longer have the heating or hot water switch itself on automatically - I switch on manually when required. In particular, in the morning I like it to be cold, as I do 30 mins on the exercise bike, and that's best when the living room is about 16C (and it actually increases the living room temp by about 1.1C). When I'm working at home, I just heat one room using an air-sourced heat pump. I can find I haven't used the heating all day quite often, even in the winter, in which case there is a heater in the bedroom if it's cold when I'm thinking of going up to bed (I do like a warm bedroom).

However, I can remotely turn on/off the heating, and I use that when I'm coming home.

BTW, I think there should be a £10/unit FIT for exercise bikes ;-)

[ss]

and insulating

I agree, have already done cavity wall and loft insulation, draughtproofing is next on the list.

[Stephen H]

To the original poster,

Have you thought about replacing the timeswitch AND the wall thermostat with a Programmable thermostat?

In your existing system, you have heating off vs Heating on at XX°C.

You have no way of having different temperatures during the course of 24 hours or over a week to suit the lifestyle of the family.

I have 2 programmable thermostats, the SALUS ST620, one for upstairs zone on 7 rads, and one for downstairs on 7 rads

At the moment i have it set to:

heat house to 18.5°C from 6.00am to 7.00am We get up at 6.30am and depart for work at 7.30am.

Heat house to 5°C from 6.30am till 5.00pm. No point heating house when we are all at work, but we want frost protection at 5° to avoid burst pipes.

Then we have heat to 18.5°C from 5.00pm till 10.00pm. I leave work at

5.00pm, arriving home at 5.30pm.

Then heat to 14°C from 10.00pm to 6.00am Upstairs only and 5.0° frost protection downstairs only as then we are all upstairs in bed, covered by duvets and cuddling wifey and there is no one downstairs.

The Salus ST620 are only 60 quid and are very flexible.

It has a daily mode, a weekdays (5) and Weekends (2) mode and a 7 day week mode. You have can up to 4 set points per day.

It also has a holiday mode so it then turns into a frost protection thermostat when activated before you go on Holiday.

My last house was a 2 bedder (Which I still own and now rent out), and my new house is a 5 bedder. I pay less in gas each year for my 5 bedder than my tenant does for his 2 bedder.

The Programmable thermostats allow you to use gas in a much smarter way more closely matching ones family's lifestyle.

[Stephen H]

As far as hot water is concerned, if you have the hot water too hot, the DHW HE in the boiler will scale up and so will your hot water pipes.

If you have the hot water temperature too low, you can be at risk of catching legionnaires disease. So most hot water is set at 55°C to 60°C to avoid either scaling or legionnaires.

With regards to the radiator water temperature, what you need to ensure is that the returning water temperature is less than 60°C for the condensing to take place and hence improve efficiency.

so the flow radiator water temperature should be adjusted such that after allowing the temperature drop across the rads the returning temperature is at say 55 °C or less.

This is where balancing the rads is very important in a condensing boiler system.

I have all my rads adjusted to a temperature drop of 15° which means i can have a flow output temperature of 65° and the returning temperature is 50°C

My rads are deliberately oversized for the rooms so I can have lower flow temperatures as that also reduces risk of burns to kids and elderly as well as ensuring condensing as much as possible.

Radiator Balancing is easily done, there are guides in how to do it.

Regards

Stephen.

[ss]

My apologies for wording, The system I have does indeed have a programmables thermostat, its a drayton and allows various settings although it controls all for the full house, thats not too much of a problem as we only use the loo and 1 bedroom upstair so all the other rads are off upstair (frost setting).

[Stephen H]

In that case the time control box is totally unneccesary considering you always have nearish instant hot water upon demand and you have a programmable thermostat that has a clock in it.....

[F]

OK, I've Googled for it but got nowhere, enlighten me...

[Andy Burns]

[F]

Ah, what a let down! I had got as far as She That Would Not F??? Indoors, but couldn't think of anything for the F...

[ss]

Slowly getting it sorted, moved into the house 18 months ago and with all the diy the heating wasnt a priority other than it worked, it took me ages to work out the time clock/thermo as my previous system had seperates. The bill for this quarter last year was £510 (gas & elec) this year I estimate £410 so taking into account price increases its going the right way. Better draught proofing and carpets should complete the job got cheap and badly laid wooden stuff on all downstair rooms. Having taken daily readings for a couple of weeks now I am confident of getting my combined bills down to £1000 for the year, at least thats my target.