Heating Issues A rated house

wolfyboy555

I have recently moved into a new build house rated A3. I have been having issues with the heating over the past number of weeks. The heating is an ideal gas boiler with a zone for downstairs a zone for upstairs then hot water separate. I have a basic mechanical thermostat in the hallway and then in master bedroom. The issue is the house doesn't seem to heat up as quickly as I would expect for an A rated house. Recently in the cold weather I could have the the heating on for hours on end and the house would barely be getting up to 20 degrees downstairs. I am just wondering how fast should a well insulated house heat up to a decent level if everything was working as it should? I would have thought that if the heating was on I should be able to raise the temp by a few degrees relatively quickly but maybe I am mistaken.

The wall thermostats seem to be off by 2 degrees as I bought a seperate room thermometer which would show 19 C when the thermostat is at 17 C for example. What I am trying to do is leave the heating all 24/7 to try and maintain a constant temp of 20 C and have the boiler kick in and off as required but I can't seem to get this to work. I should mention I have the all the rads at 5 on TRV and have bled them all.

John.G

A idea of the boiler Output, its set point and actual flow temps + rated rad outputs will tell a lot, also, if easily available the boiler return temperature.

My own house (certainly not A rated) gets up to 20/22C in 2/2.5 hours even on the coldest mornings of say -3C to 0C, I have a 4 bedroomed house with a 20kw Firebird boiler., boiler SP temp is 75C.

Deanicus

Sometimes, getting that A rating means a lot of ventilation, either mechanical systems or even just large vents on the windows. As you can imagine, the window vents are not great for heating a home due to the constant stream of fresh cold air coming in

Usually you can close them (or adjust the mechanical system) but that has it own issues when it comes to air quality and humidity.

I would also check your windows/doors for draughts as the house might have been rated as A3 based on design but the actual build could have issues with insulation etc

Another thing to check is your boiler temperature. If it's too low, the rads might struggle to heat the space

What temperature are you starting from that it takes hours to get to 20?

homer911

https://www.boards.ie/discussion/comment/118447706#Comment_118447706

Wow, 75C is very high. The magic numbers from an efficiency POV are 18-21 C for the rooms and 55c for the boiler

John.G

Its the return temp that determines any boiler efficiency. I have TRvs on all boilers so once the rooms are up to temp quite rapidly IMO, the TRvs reduce the return temps from ~ 62/65C to 45/50C, a bit academic in my case as I have a SE 16 year old Firebird boiler with a flue gas temp of ~ 230C, I don't really know what effect the reduction in return temp this has on my flue gas temp.

blackbox

OP did not state heating method. If it is underfloor heating there may be a big lag until the set point is reached. Underfloor is intended to be used long term rather than be switched.

If using radiators, it should only take an hour or max two hours.

Wearb

https://www.boards.ie/discussion/comment/118449289#Comment_118449289

"I should mention I have the all the rads at 5 on TRV and have bled them all."

From OP's post.

Flinty997

How do you know its not leaking out through drafts etc.

wolfyboy555

Thanks for replies. To clarify some points raised:

House is a 4 bed detached house

I have the boiler set to about 3/4 where there is a little e symbol. The boiler temp is in and around 67-70 degrees when operating.

Not sure how to check boiler return temp? or indeed the radiator outputs?

Came home just after 6ish this evening and temp was at 17.9 and stuck on the heating....it was up to 19.2 a little after being on two hours.

Ventilation is by 6 inch vents in the walls. I have temporarily filled these in with insulation (against most advise on here I know) and have been using trickle vents on windows to supplement for time being. However I have closed all these also certain times to see if any difference and nothing major.

ongarite

You should have the boiler dial at e. This has boiler temperature of 70 and at most efficient.

What.Now

Have a look at the temp stats and see if they need recalibration.

If the room temp stats control the boiler and they are coming up as 21 Deg C but the true temp is 19 Dec C then the room temp stat is telling the boiler that no more heat is required and therefore the temp stays at 19.

If the house is designed to A2 then any mechanical ventilation will have been designed to ventilate the house and allow it reach design temperature with the required regulations in mind.

It's a new build so an air leak test would have taken place if I'm not mistaken and therefore that would rule out drafts otherwise it would not have achieved an A2.

Check the stats first would be my recommendation.

afatbollix

I moved into an A-rated new build 4 years ago, First winter was horrible, the Heating was on all the time and the place never heated up.

It was all down to cheap tiny radiators. They were single-sided and quite small.

I bought a couple of double-sided radiators for the main rooms and it changed everything! The place warms up quickly now. Most days the heating is on an hour and that's it. I spoke to someone about it and our theory was to get the A rating they had to have the small radiators.

What.Now

https://www.boards.ie/discussion/comment/118452500#Comment_118452500

That's disgraceful if that's what has happened

blackbox

https://www.boards.ie/discussion/comment/118449447#Comment_118449447

Oops! Missed that!

John.G

https://www.boards.ie/discussion/comment/118452198#Comment_118452198

If you have the time/inclination, measure each rad's Height X Length in cm or mm and state if single or double and we can soon see what the installed rad output are. If you can't find the time for this just measure one or a few of your main room ones and that will be indicative of the others.

Also can you post whether gas or oil boiler or maybe a heat pump and whatever make/model.

Flinty997

Are there any rooms better or worse for heating up?

afatbollix

https://www.boards.ie/discussion/comment/118452582#Comment_118452582

Also could of been a cheap developer. Which is more likely. It's the only thing I had to change in the new build so hasn't been too bad. I've heard of 100+ snags and for about £40 I was sorted with a couple of new rads which I changed myself. My heating bill is now £27 a month.

Domicio

I had similar problem on my place and fixed it resizing the rads as it wasn't generating enough heat.

What is the size of each room and the size and model of each rad?

edit: I'm also about to add an extra rad close to the kitchen island as we normally have people coming over for drinks that goes over night while we are not cooking, which makes the area extremely cold.

So everything depends also how you operate rather than what you will be reading around of people saying that you barely need a rad in the kitchen (just as an example). I see it as an old way to think, where the kitchen was only used to cook and you would have a meal in front of the fireplace.

edit2: I've also replaced a single rad to a double rad in one of the "bed"rooms. Even the plumber said it would be too much but I use it as an office (working from home) so when it is on, I'm not under a comfy duvet and it is unsustainable be using multiple layers while working.