Radiators not getting hot enough

scan

My radiators are only hearing to around 40 degrees - I’m told it should 60 degrees plus.

My rads are bled so that’s not the issue.

When my boiler is on, it also heats the hot water - this gets very hot.

I’ve tried varying the temp on the internal controls and the ones out at the boiler as well - it seems to make no real difference

I’ve a firebird popular 90

Any help or advice would be really appreciated

Carry

Had the same problem but with a very old heating system in the house.
The rads had apparently a lot of residue inside, from corrosion or limescale or whatever. I've got them flushed and they are fine now.

John.G

scan wrote: »

My radiators are only hearing to around 40 degrees - I’m told it should 60 degrees plus.

My rads are bled so that’s not the issue.

When my boiler is on, it also heats the hot water - this gets very hot.

I’ve tried varying the temp on the internal controls and the ones out at the boiler as well - it seems to make no real difference

I’ve a firebird popular 90

Any help or advice would be really appreciated

Is your system zoned? ie have you separate motorized valves for say u/stairs, d/stairs and hot water and have you roomstats? If you open up all the radiator zones (with roomstats, if fitted, turned up to max and set the boiler stat to say 75C (if like my F/bird 90S) about 3 notches up from the stat minimum setting then just time the on and off cycling times of the boiler approx. 25/30 minutes after a cold start then that will give you a good idea of how much the rads are emitting.

scan

Thanks for replies

Carry - My house isn't that old, built in c2006 - but I do have limescale issues. I can understand how this would give cold spots (like when a rad needs to be bled), but my rads heat up all over - they just don't get warm enough anywhere.

John G - I'm not sure what you mean to be honest. I have 2 zones - bedrooms and everywhere else. At various times I've tried to turn all of the controls I have to their max to see if it makes any difference, but it doesn't (at least not a noticeable difference).

My zoning system is very basic - pic attached,

Thanks again

MuffinsDa

Carry wrote: »

Had the same problem but with a very old heating system in the house.
The rads had apparently a lot of residue inside, from corrosion or limescale or whatever. I've got them flushed and they are fine now.

by flushed, you mean having the whole system powerflushed professionally?

TheW1zard

Try flush the system by turning all radiators off and open them 1 by 1 starting closest to the boiler.

John.G

scan wrote: »

Thanks for replies

Carry - My house isn't that old, built in c2006 - but I do have limescale issues. I can understand how this would give cold spots (like when a rad needs to be bled), but my rads heat up all over - they just don't get warm enough anywhere.

John G - I'm not sure what you mean to be honest. I have 2 zones - bedrooms and everywhere else. At various times I've tried to turn all of the controls I have to their max to see if it makes any difference, but it doesn't (at least not a noticeable difference).

My zoning system is very basic - pic attached,

Thanks again

Limescale should have nothing to do with the heating side of your system as there is little or no make up required throughout its life, but could be sludge alright.
As I said earlier if you just sit and listen and time the on/off times of your Firebird then it will tell you very fast what the total rad output is and you can take it from there.

Latro

There is too much flow going into the hot water cylinder vs radiators.

There should be balancing gate valve somewhere on the flow pipe just before it enters the cylinder.

It needs to be turned down to nearly full close.

scan

Thanks for feedback folks

I had some wrong info - my tank does not heat up any more than the rads - everything only gets to around 40 degrees

John.G

If you feel the outlet (flow) pipe just where it exits the boiler, is it appreciably hotter than 40C??, if its around 70/75C you will barely be able to keep your hand on it.

TheW1zard

Boiler thermostat too low?

John.G

I think that (boiler) thermostat cannot be set lower than 65C....certainly not lower than 60C, of course the stat could be faulty.

scan

thanks again - is there anyway to test a faulty thermostat ?

I seem to have all the symptoms

John.G

One (crude) way is to stand at the boiler and as soon as the burner cuts out just turn up the thermostat setting, the burner should then immediately restart. I'm a bit surprised that there is a 20C? difference or so, can you just check that the probe(s) is pushed fully home in its pocket.

scan

Hi

Just a quick reply to let you helpful folks know what happened.

I got a plumber out and he changed the jet in the boiler from a 0.5 to 0.6 (the only spare he had in his van) - the change was unreal - I now actually have hot rads. So I'm assuming that the jet I had was partially blocked or something, because I couldn't imagine the extra 0.1 making such a difference - but I could be wrong.

Thanks for taking the time to help

Wearb

scan wrote: »

Hi

Just a quick reply to let you helpful folks know what happened.

I got a plumber out and he changed the jet in the boiler from a 0.5 to 0.6 (the only spare he had in his van) - the change was unreal - I now actually have hot rads. So I'm assuming that the jet I had was partially blocked or something, because I couldn't imagine the extra 0.1 making such a difference - but I could be wrong.

Thanks for taking the time to help

It's a 20% increase. What pressure did he set the pump to?

Wearb

scan wrote: »

Hi

Just a quick reply to let you helpful folks know what happened.

I got a plumber out and he changed the jet in the boiler from a 0.5 to 0.6 (the only spare he had in his van) - the change was unreal - I now actually have hot rads. So I'm assuming that the jet I had was partially blocked or something, because I couldn't imagine the extra 0.1 making such a difference - but I could be wrong.

Thanks for taking the time to help

It's a 20% increase. What pressure did he set the pump to?