How to Fix a Boiler Pump - Low Flow / Boiler Overheat - Surprisingly Cheap

[@ek8710]

Very handy, thankyou!

[@comeinhandynow]

Cheers

[@GaryHerberson]

I upgraded my water pump to a newer style invertor motor system. Straight replacement with no additional plumbing. The type used in this video would use something like 60 watts when running. Invertor motor uses about 20 watts. Payback was calculated to be about 2 years as these can be pucked up fairly inexpensive off the Internet.

[@comeinhandynow]

Thanks, interesting. Yes 70W on this one.

[@GaryHerberson]

My brother is a plumber and has warned me of over speeding the radiator water pump. This could lead to a situation where hot water is pushed up to the loft feed tank, causing damp issues and of course wasted heat losses. Not applicable in this video, a warning to other ussers tho.

[@comeinhandynow]

Thanks for the feedback, but that doesn’t make sense to me about the header tank, as a higher speed on the pump doesn’t increase the system pressure (as you can see on the pressure gauge on a closed system). It’s higher output push is balanced by higher input suck, so pressure at the header tank would be unchanged. To push water out of the header tank, water has to come from somewhere, which it can’t.

[@GaryHerberson]

@comeinhandynow long time since I was at college and tbh, I don't know your setup. I did catch the pressure gauges in the video and these of course work great in static operation. As you have a loop system (dynamic system), you would need a Venturi tube system setup to measure accurately. Where does the pressure come from, you ask? Heat rises and IF the rads don't dissipate the heat, this will rise up and into the header tank.

[@GaryHerberson]

You haven't got a combi boiler have you? I assumed it was a BBU

[@comeinhandynow]

@@GaryHerbersonno a closed system with hot water cylinder

[@PhilRiley-v9n]

​@@comeinhandynow I've experienced this issue with the boiler system in our church. If I put the pump speed up to position 3 then the return flow to the boiler also gets pushed up to the header tank about 5 metres higher than the boiler. If I drop the speed to 2 or 1 then this overpumping stops