Circulating Pump

[BoilerPro]

Normally I do domestic boiler related work but doing a job on a Creche at the moment. There are 18 rads, 16 of them doubles, run by an RDB4 burner and a Firebird 250 if memory serves me right. The puzzling thing is there is only a normal domestic 3 head grunfoss circulating pump installed. I know it's particuarly cold at the moment but the burner is running constantly using a lot of fuel. Would changing the circulating pump to a 5 head help it to reach temperature any quicker thereby cutting down on fuel consumption?

Kevin

 

[Renewable M]

that riello must have a hell of a nozzle in it. for a start unless the structure is seriously old/huge heat loss that is a mammoth boiler.

I surveyed a job in north yorks moors for one of our installers, before last winter. There was a trianco 240,000 btu model (non condensing) in place using all the oil in the world...... and when i did the heat loss calcs they needed a peak of 110,000 btu. We changed the boiler for the correctly sized model, eliminated the massive, massive inefficiencies and after the winter they reported a 60% reduction in oil use.

When I called the previous 'installer' he said "a big house like that with stone walls needs something meaty mate." Staggering

That boiler of yours should have 35mm pipe coming off I think just to get the heat away.

More info would be useful.

 

[BoilerPro]

Yeah, it's speced for a 1.75. Had a 1.5 in it but it just wasn't reaching temperature quick enough. Changed it for a 2 gallon and it's running better. Not sure what pipe is coming off it and I won't get to see it till the New Year now as the creche is closed till monday week.

The whole job is a mess. Half the rads downstairs needed balancing and bleeding, and all the trv dials were about to come off. I think his brother did the plumbing and he's since fallen out with him! I sorted one of the rads that was only barely showing signs of heat but had to switch every other rad off to get anything into it. Even at that I could get no response to bleeding it. Neither air or water came out and it took an age to balance, yet most of the other rads that needed bleeding bled with no difficulty. Two of the rads are still stone cold and I can't get anything into them, but I ran short of time and will go at them again after the hols.

Will find out more when I can. What additional info would help?

Kevin

 

[Deleted member 2053]

Rads that fail to get warm even with everything else turned off would tend to suggest that the pump pressure is insufficient. Assuming of course that it is piped correctly. If you have a powerflush unit you could swap that in for the pump and see what difference the higher pressures and flow rates made. It would also help to clear airlocks of that is causing you grief.