Hi all

The pump fitted to my heating system has a two speed setting, gravity system with pump on return, just wondering how you decide on the two settings, is it technically based or just see how the system heats up

Oh and while I’m on the subject lack of flow through hot water cylinder, coil blocked. any experience of system flushing

I think my systems telling me something 🙁

Turn the pump to low in summer, when you just want HW and to high in winter when it has to drive all the radiators. I bought a pump which adjusts it’s speed based on flow, so as the radiator thermostats switch off, it backs off the pressure to save electricity / pump life.

Oh and while I’m on the subject lack of flow through hot water cylinder, coil blocked. any experience of system flushing

You could try Fernox DS40 in the system (check it’s compatible with your boiler as it’s a bit aggressive).

Fernox is great. I de-sludged my system when I first moved in and removed a right load of crap out of the system. it massively improved the efficiency of the system.

I also reduced the speed of my circulation pump. I noticed that the pump was making a loud noise accompanied by the noise of water rushing, so I switched the pump to its slowest speed and all has been fine since.

Turn the pump to low in summer, when you just want HW and to high in winter when it has to drive all the radiators.

Bit of a simple approach there fella. Have you ever balanced your radiators around the house or are you just using the pump to force the water around? If the system has been designed and set up properly, it might work fine on the lowest setting.