Boiler wiring

31 Mar 2004
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United Kingdom

I know how a boiler system works came across a sticky situation today i think i know how to overcome it but would like your thoughts. Their are no manuals to ref. from.

Basically, i have a keston condensing boiler with a megaflo tank upstairs. wireless room stat, mid position valve and a programmer. Ch is all on one zone. the boiler has a pump over run. How do i wire it to have a pump over run so when the HW and CH has finished calling for heat to keep the pump going. My thoughs are their is a pair of contacts in the megaflo which has a perm live and a sw line back to the boiler which allows the pump to keep going until heat is pumped away from boiler.

let me know what you think.
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wire the pump (if not in the boiler) from the pump terminals in the boiler. The boiler then controls the pump and runs the pump if needed.

It only needs to get the hot water away so it does not lock out.

If there is no pump overrun from the boiler it probably does not need one. Did hear they were changing this so that there was no need to run the pump as a waste of power though.

I would not attempt to wire anything back from the Megaflow as you could invalidate the megaflow warranty if not designed etc


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