Zoning

[HomerSimpson]

A few years back I remember that the experts were pushing zoning of the central heating system using separate pumps on each radiator loop instead of valves as the pumps are only about £40 each. Is this still common practice?

If it is, it might suit me as I have a new extension to first fix etc but could do with getting the old part of the house heated again. I'm thinking of 4 zones ie. 1) existing downstairs 2) existing upstairs 3) new downstairs 4) new upstairs. Am I right in saying that it is just a manifold of pumps all connected to the boiler and that they could be added one at a time?

Any views?

 

[ChrisR]

Yes, its common on larger systems to use a "balanced header" which is a thumping big pipe which is a loop from the boiler to the boiler, and smaller pipes taken off for each zone, with pumps of various sizes. You can do the same sort of thing domestically without using huge pipes. You have to be a bit careful with your flow rates through the boiler and on each loop. Usually you don't need a pump for each loop, and can use just one pump for the lot. Auto bypass valve(s) become vital

If your boiler is less than 28kw or so then depending... a 15/60 (6 m pump) will be able to pull enough water through the boiler that you're getting all the power out of it.

You can have a one-radiator zone if you want - all it takes is a programmable thermostat and an electrically operable rad valve head.