Multifuel back boiler with HWC in cellar

[Stewartt19]

Hello all! I’m hoping someone can answer a question about our heating system. We are currently renovating a large Victorian property. The heating system is biomass (wood pellets) and costing us a fortune! We were planning on installing a multi fuel burner anyways so I’m thinking I may as well get one with a back boiler and plumb that into the HWC too ( I purchased a cylinder that allows this so no problem there!) the issue I have is the stove will be on the ground floor and I plan to have the HWC and all other ‘plant’ in the cellar. I’m not so keen on adding pumps to the system as we are in the middle of nowhere and in the winter get power cuts quite regular.
So the question is… if I had the sacrificial radiator on the floor above the stove, say in the bathroom, and a header tank in the loft would I get sufficient circulation through the system baring in mind the pipework would leave the stove and go down into the cellar before heading up to the radiator.
Either way I think of running the pipework it always has to go down through the floor before heading up unfortunately, purely because of where everything is.
Thanks in advance!
Stew

 

[stem]

My experience is with heating system controls, but along the way I've picked up some basic info from the plumbers I've worked with, and as no one else has commented so far........

I would say probably not. Gravity circulation requires the use of large bore pipes 28mm as a minimum. This is because gravity circulation is slow compared to pumped so to get the required heat flow a larger diameter pipe supplies a larger volume of water but at a slower flow rate. Forcing it through a 'sacrificial radiator' with its restricted flow and 15mm pipes would likely prevent any useful flow rate being achieved.

Another basic design is that the boiler is at the lowest point and that the pipes slope upwards towards the cylinder, and downwards from the cylinder, and I doubt that would work very well with a loop down to the cellar below it the coolest water will fall to the bottom and there's no heat source there to make the water less dense so that it rises back up again.

I notice it's your first post, so I hope you don't mind me saying that you probably haven't received any replies because you posted your question in 'Trade Talk' The instructions at the top of the trade talk forum say "Talk for the trade to discuss trade related topics e.g. quotes, customer issues, etc. Do NOT place general queries here". For future reference the Plumbing and Central Heating forum would have been a better choice. That's where the folks in the know about these matters hang out.

 

[Stewartt19]

Thanks for your reply. Yeah not really a computer person and never used forums before! We’ve opted for a battery back up system which we can add solar panels to eventually so no fear of the pumps not getting power!