Is this how it should work

[André]

I have a potterton profile 80e which supplies 12 radiators via a Grundfos pump. There is a hot water cylinder which is vented.

I am not sure if the system is working properly ( recently moved in ) when the heating is switched on all the radiators heat up but fine but once the hot water comes on then all the radiators seem to cool down and two downstairs radiators almost become cold unfortunately one of these is in the sitting room. Once the water heats up the rads become hot again, but if you run a tap for long periods then the rads go cold again I can only guess that the motorised valve is diverting the hot water from the boiler to the cylinder and starving the rads. The pump is set to no2 but not sure if I should turn this up.

 

[Agile]

Some systems are designed to give priority to hot water.

Other systems effectively give some pririoty to hot water because the flow resistance is lower.

If your system is the latter then you can rebalance it by putting a restrictive valve on the connection to the cylinder heating coil.

Tony Glazier

 

[André]

Dear Tony Glazier......Thanks for letting me know that there is probably nothing wrong with my system. I am still getting used to it, at least now I can rest easier. Many, many thanks for your reply and sorry for not replying sooner.

André