Condensing boilers: getting the return temperature low enough

[Man at B&Q]

Controllable ones are PMSM with appropriate drive electronics.

MBQ

[Tim Streater]

I just looked at my water pump to get the name/model. It's a Grundfoss Selectric, you could just giggle for that to find out how it works. It has a three position switch that controls the rotation speed.

[Dave Liquorice]

Maplin did have a two thermocouple thermometer for not many notes, donno if they still do. Does F and C, T1, T2 and T1-T2.

Couple a large croc clips lined with firm foam make for quick attachment of the thermocouples to the radiator stubs quick and easy.