Combi Boiler and Pump: rate of radiator heating

[Possom]

With regards to the Worcester Bosch Greenstar 30i Gas Combi Boiler below, the description states that it has "a low energy pump to reduce electrical usage".

https://www.boilerguide.co.uk/productinfo/worcester-bosch/greenstar-30i

So this, presumably, is an internal pump as opposed to using an separate pump. Does the pump essentially determine how quickly the radiators heat up?

If so, can the pump rate be increased, and if not, is it possible for a suitable qualified person to add an external separate pump which would increase the rate at which radiators would heat using this boiler?

Thanks.

 

[muggles]

Yes, it's an internal pump. No, the pump does not determine how quickly the radiators heat up, and an external pump would not only not cause them to heat up more quickly, it might damage the boiler when it's generating hot water. The internal pump can be adjusted, but only to reduce its power, not increase it. On its present setting it is linked to the burner output - if the burner is firing at maximum, then the pump will run at maximum too. If the burner reduces to 50%, so does the pump.

Maybe you should start by describing the problem you have, telling us a bit about your system, and we can advise from there?

 

[Possom]

Maybe you should start by describing the problem you have, telling us a bit about your system, and we can advise from there?

Thanks Muggles.

I have a radiator as shown below in a relatively small 9 sqm room with the radiator below:
https://www.radiatoroutlet.co.uk/1800-x-470mm-white-vertical-traditional-3-column-radiator

My system uses the Greenstar 30i combi boiler:
https://www.boilerguide.co.uk/productinfo/worcester-bosch/greenstar-30i

It can take in the region of 4.5 hours to warm up to 22C in the room when the boiler is set to the recommended "e" setting, that is, the central heating system is at about 60 C.

I would have the rad up to full setting, and the external wall is cavity wall insulated (mid terraced house). I know at a relative's house (different boiler and rad), it might take, say 30 mins to warm the room up.

 

[muggles]

Is the radiator itself heating up properly all over? Was it fitted in the correct orientation - there will be an internal baffle which should be on the flow side? Does it work properly if you turn all the other radiators off in the house?

22 is very hot, I'd be in my shorts & t-shirt at that

 

[Harry Bloomfield]

It can take in the region of 4.5 hours to warm up to 22C in the room when the boiler is set to the recommended "e" setting, that is, the central heating system is at about 60 C.

4.5 hour to increase to 22C, but beginning at what temperature?

 

[Possom]

Is the radiator itself heating up properly all over? Was it fitted in the correct orientation - there will be an internal baffle which should be on the flow side? Does it work properly if you turn all the other radiators off in the house?

22 is very hot, I'd be in my shorts & t-shirt at that

Yes, the rad heats all over. The manufacturer states the the rad can go on either direction,so either side can be flow or return. It's still the same when other rads are off.

It's just a cheap thermometer which I have, so it's possible that it's out slightly. The room feels okay when fully heated, but it's certainly not extremely hot. I know at my relative's house when they turn their heating on full, the heat in the room is very warm. The heat in this room is nowhere near that warm.

 

[Possom]

4.5 hour to increase to 22C, but beginning at what temperature?

I've tried it early morning when the room had been at 14C.

 

[Harry Bloomfield]

If as you say the radiator is getting hot all over and remaining hot all over, then it just leaves three possibilities..

1. The radiator is undersized for the space it is supposed to heat.
2. The rooms fabric has a large thermal mass.
3. The room/house is badly insulated/ drafty.

If your 14C measured early in the morning, was the morning after the room had been up to temperature the evening before, then it suggests 3 is at least part of the issue.

For reference...

My home was at 21C when the heating went off at 11pm last night. I got up at 6am this morning, outdoor it was 0.7C and the temperature indoors had dropped to 17.7C. My heating had not fired over night. So I nudged the stat up to 20C and twenty minutes later the heating shut off at 20.2C.