Help with new central heating system

Alibali

Hi,

I moved in to a new build at the end of Sept, we have gas central heating, controlled by a thermostat in the hall. Now I have the thermostat set at 22, so in theory when the temp drops below 22 the heating should kick on to bring the temp up.

However, some of my radiators at set at setting 3 and some are set at setting 1 or 2 (depending on the room i.e the kitchen doesn't need much heat as its small). I have noticed that when the heating kicks on, the radiators that are set at 3 come on and heat up, however, the heaters set at 1 or 2 are stone cold. This is not what I want, i want them on at a low heat just to take the chill off the room.

I have spoken to the site manager, but he is not very clear on whether this is right or who they are sending out to look at it.

My understanding was - the temp falls below 22, the heating kicks on, all radiators heat up to the various settings and heat the house to 22, then the heating turns off. So why are some of my radiators not coming on at all? (note: they do work if i turn them up to setting 3, however, my house would be like a sauna and its a waste of money)

I am quite concerned as the back bedrooms are pretty cold by the morning as those heaters are set at 2 (and they are not coming on overnight), this would normally be ok as they are empty at the moment but as we are having a baby I need to get this sorted.

Any help/advice would be grateful as I want the house builder to sort it but they seem more interested in telling me that its fine and trying to baffle me, than actually trying to help.

Thanks

Pincher

Turn them up to five.

Alibali

the house would be roasting if I turned all of my heaters up to five.

macman

Turn the rads up to full and the room 'stat down to 20C or 21C. Experiment a little if that doesn't work, turn the rads down locally as required.
All the TRV does is adjust the temp at which the valve opens or shuts.
It would not be 'roasting' if you turned the room 'stat down to a more normal temp. 22C is on the hot side for most people.

WestonDave

Radiators aren't controllable for temperature in the way you are implying - they are either on or off. The thermostat on the end opens if the temperature falls below a certain level and allows hot water into the radiator (which will heat up to the temperature of the water). When the room reaches the right temperature the thermostat will then shut off the hot water and the radiator will cool down. It may cycle like this many times whilst the overall heating is on.

So its likely that the radiators set at 1 or 2 are not coming on because the room is warm enough for the thermostat to stay closed. If you turn it up to 3 it will warm up until that room is warm enough.

You have two more tools in your armoury to adjust - firstly to a degree you can adjust the output temperature of the boiler. You might find that if you turn the boiler heat down a bit (not too much as it could cause legionella to form in the system according to some) the radiators won't get so hot which might make them a bit more controllable. (If the thermostat shuts when the radiator is red hot it will take some time to cool so all that time it is still heating the room - if its a bit cooler it won't overheat the room for as long).

The other thing is to maybe turn the thermostat down - we run ours on 18C - maybe 19C on a cold evening, with it set for 14C overnight. Our house is relatively well insulated as yours should be if its a newbuild. Again this might help as it will be turning the system on less.

macman

PS: the temp of the rad is not what matters-it's the temp of the room! The rad is either 'off' or 'on'.

Alibali

WestonDave, someone else suggested that the radiators in the rooms upstairs were not coming on because the temp in the room was sufficient, so I bought a thermometer and put it in the back room and it is showing a good 4/5 degrees below what the thermostat is at downstairs. So I cant understand why the radiators wont heat up in these rooms unless they are turned to setting 3. If you have your thermostat at 19, what setting do you have your individual radiators on at?

The house is pretty well insulated, the heating only really comes on at night when the temp drops and by morning the back rooms are pretty cold as those heaters wont come on.

Macman - I am quite happy with the temp at 22, I do feel the cold more than others and being pregnant I am not keeping that well, so needs must. The reason it is at 22 was because we could not find a happy medium, but I will try turning the thermostat down and radiators up to four or five and see how we get on, but as it stands anything above 3 and the radiators are pretty warm.

Alibali

macman wrote: »

PS: the temp of the rad is not what matters-it's the temp of the room! The rad is either 'off' or 'on'.

I didn't realise this either, I thought the higher the setting on the radiator, the more gas/money was being wasted. Previous flat had storage heating, so trying to get to grips with this new heating system.

macman

It's better to turn the rads up to max, set the room 'stat down to whatever you are comfortable with in the main living area, then adjust the individual TRV's down one by one as required.
The system will have been balanced with all the TRV's on full.
It's quite normal to have bedrooms 3 or 4C cooler than a living area.
Stop worrying about how warm the rads feel, that is simply not relevant.
Your gas bill is mainly determined by how long your boiler is running for. If you turn the rads down a notch, you are still circulating hot water through the system according to the demand called by the room 'stat.
If you really want to save gas, then stop leaving the boiler on all night. It's not necessary, especially in a well-insulated new build. Or at least only in extreme cold, which we don't have here yet this winter.

Alibali

macman wrote: »

It's better to turn the rads up to max, set the room 'stat down to whatever you are comfortable with in the main living area, then adjust the individual TRV's down one by one as required.
The system will have been balanced with all the TRV's on full.
It's quite normal to have bedrooms 3 or 4C cooler than a living area.
Stop worrying about how warm the rads feel, that is simply not relevant.

Well i will give that a go tonight and see how I get on with it over the next few days, hopefully we will get it sorted out. I was just worrying wasting gas/money with the radiators on too high but as you said, the temp of the radiator doesnt matter.

Alibali

I dont leave the boiler on all night, I have it on a timer. So it is off completely during the day, and only on for an hour at night and for half an hour before we get up.

It has been quite cold here though, had to scrape the car this morning and a few mornings in the last week or so. However, where I live we are up higher which is why its colder.