Adding pump over-run?

[JC22024]

I have a new Firebird Silver Boiler House model oil fired room heat only. I note in the manual all other models in this range have pump over- run connections. But not mine:



The circulator pump is wired with the boiler. So when a zone valve opens the boiler and pump both get 240v.

Could a pipe stat or similar be used in order to provide power to the pump so it runs momentarily after the boiler shuts off to remove the excess heat and put it into the circuit? Or not worth looking at?

It's a 2 Zone system so I suppose it would also add complications to the zone valves. Ie would need wired in such as way that it gets powered by the zone valve opening and keeps it open until no heat calling and temp satisfied. Problem is with 2no zones that could be 2no stats any maybe a headache getting it to work.

Just wondering if anyone has retrofited pump run on.

 

[ShaunCorbs]

Time delay relay once switch live cuts it runs the load on for x amount of time

 

[John.g]

I have measured my Firebird flow pipe a few times over the years after boiler shutdown and the temp rise was 20/25C from a burner off temp of 70C which is - 0.6kwh. If you captured this every time the boiler cycled then obviously huge potential savings but the circ pump only stops when room stats and cyl stat or is programmed off which may be 3 or 4 times/day, even then if you have pump overrun the boiler will still have to make iup the previously captured 0.6kwh the next time it fires up, you will only gain what energy is lost to outside due to radiation losses, say 1/2 of 0.6kwh X 4 times/day, or - 1.2kwh/day, easy to calculate your savings then based on fuel costs, based on my kero fill yesterday, £0.08/kWh so max of 365x1.2x0.08, £35/year
Maybe add another 0.6kwh/day for overnight loss which otherwise would have gone to the house, so savings possibly around £50/year??.