My New Combi Boiler, Help And Advice, Please

[barry1010]

Bit of background - my old boiler was over 40 years old.  It was either on or off, temperature controlled by a knob on the boiler.  I could programme the times it turned on and off but that was all.

My new boiler has a programmable thermostat in the hallway that I have programmed to 21 during the day and 17 at night.  It seems to be working well and is switched off for most of the night and parts of the day.

My average three bed house has to be kept warm 24/7 because of my oldsters.

When I first put it on I had to turn the dial on the boiler up a bit as the house wasn't reaching 21.   I have the valves on all the radiators at the highest setting apart from my bedroom where it is turned off.

This is all very new to me and I'm not sure I am using my thermostat, valves and boiler correctly.  I read the manuals that came with it but they aren't particularly clear.

How much should I expect the central heating and hot water to cost me per day?  

Thanks

[Atheist]

barry; An interesting post which leads up to "How much should I expect the central heating and hot water to cost me per day?"

I don't think that is answerable based on the info available to us.

If you keep your house at the same sort of temperature as your old boiler used to do, then it might be cheaper with your new boiler because of the new boiler being more efficient.

[barry1010]

I used the gas fire in the living room a lot last winter but haven't turned it on all since I set up the new boiler so it is impossible to compare the running costs of the boiler, although I can compare the overall heating cost

[Atheist]

barry. Isn't the overall heating cost the main issue? If you want to compare the boiler now with the boiler as was (minus the gas fire) then I don't see how to do it.

In any case, whatever the sums, the will be other factors such as the weather.

[barry1010]

You are right, of course.  I was just hoping for a rough idea as to the cost of running it. Also reassurance that I have set it up correctly.

[perseverer]

Your boiler should have controls to set the temperatures separately of the hot water, and the water circulating in the radiators. There is advice to turn the radiator output down to 60° if it is set higher without really affecting the heating in the house much. Also, depending how much heat you need in the hall, compared with the rest of the house, you could try turning the thermostat down to 20°.

[miser]

Hi barry

the TRVs on your radiators should initially set to 3 (about 20 degrees) in the rooms you wish to heat and then fine tuned with experience.  The hall radiator should NOT have a TRV fitted and the radiator valves should be fully open. 'Experts' say the flow temp on your boiler should be set to 60 degrees for efficiency but if your house fails to warm up enough you will have to increase this, mine needs to be at 70. 

[barry1010]

I don't know what the flow temperature is and there are no numbers on my boiler dials.  The hot water is hot enough to wash up without needing to add cold water so I think that is sorted.

[barry1010]

There is no TRV on the hall radiator 

[perseverer]

Barry, does your boiler display a temperature? If so adjusting a control might display the temperature you are setting for a few seconds.

[barry1010]

Silly me, I pressed a few buttons and got:

Water. Target 59

Rads.  Maximum 57

[brainiac]

What make and model is it?

[barry1010]

Logic c30

[New Judge]

It seems, barry, that with the set up you have, you may be getting conflict between the room thermostat in the hall and the TRVs on individual rads. The room thermostat will cut the heating off entirely when it reaches 21/17 in the hall. That means there will be no heating supplied anywhere in the house though the temperature elsewhere may not have reached 21/17. Similarly in reverse, the hall may be cold (and so the heating still operating) but your other rooms may be hot enough. Since you have all the TRVs on maximum, they will continue to provide heating in those rooms until the thermostat in the hall shuts it off,

I have mine set up precisely the opposite. I have a room thermostat set to maximum (which is about 28, I think) but control the heat in each room by adjusting the TRVs as required. I never had a room thermostat at all until I had my new boiler fitted about seven years ago. I was then told it was "regulations" to have one. So I had it stuck on the wall by the boiler, set it to maximum and have never touched it since.

[barry1010]

So far the room temps throughout fluctuate between 20 and 21 during the day and seem to be around 18 overnight, with the exception of my bedroom which is unheated.

So it seems the whole house is the same temperature, which I am happy with.

[The Builder]

Twenty years ago, Barry, we were happy to have CH systems with TVRs (thermostatic rad valves) and NO wall thermostat in the hall or anywhere else. Then someone in Goverment decided this was profligate and we should do something to effectively 'strangle' the heating by controlling the overall system.

So they brought back roomstats. Consider this: you have a stat in the hall which, when it reaches 21, shuts down. Meanwhile, there's a hypothetical room somewhere in a cold part of the house 'calling' for heat, but it's never going to get it. If you want 21 in that bedroom, then the hall stat would have to be set higher than 21. Exaggerated maybe, but you can see the problem. 'Central' temperature control is inefficient and actually quite a silly notion.

Building Regs say you must have a wallstat. Ok. So override it by setting it higher than needed (say, 25). Now, each individual TRV can sense the temp. it's calling for. Result: efficient heating system.

Setting the wallstat higher is anathema to most people. This is illogical. The TRVs will always shut off when your set comfort level is reached. There is no such thing as 'wasted' temperature.

Don't worry about the hall rad with no TRV. It's a safety feature in case the returning water temp to the boiler is too high and may cause damage. It gives the excess heat somewhere to go. In practice, it's not a problem.

As far as comparing running cost with a correct set-up is concerned. You're conflating two different notions. Set-up affects efficiency. Running costs depend on your desired comfort level. If you need to reduce cost, then you have to reduce temperature.

Hope you're still with me 🤔

[The Builder]

I take too long typing. M'Lud got in there before me. 🙄

[barry1010]

Thanks, Builder.  Luckily the temp is consistent throughout

[barry1010]

Are the temps displayed on my boiler what they should be?

[miser]

If you set the wallstat in the hall to 25 degrees and your TRVs to your comfort levels in your living rooms the warmest place in your home will be the hall where nobody is staying. 

[The Builder]

......... and another thing...........  just noticed your boiler readings Barry. 59 for water is well hot enough. 55 would be plenty... even 50.

57 for rad temp is low. Received wisdom says 60-70. No more though or the 'condensing' efficiency is impaired.

57 on cold days could result in constant boiler cycling while it thrashes away trying to get up to the temp you need in the rads. Agian, this is NOT wasteful. The TRVs will simply shut off.