Rads get warm when hot water is on, SYSTEM BOILER AND MOT VALVES ARE WORKING CORRECTLY

[JC03]

After some ideas, I've got a house which is installed with a system boiler, when the hot water is turned on using the programmer the radiators also get warm, checking the pipework underneath the boiler, both the how water flow and central heating return are red hot! Any ideas how to rectify?

Cheers

 

[Deleted member 32524]

Your 3 port or one of your two port valves are stuck, allowing hot water to pass into the heating circuit

 

[JC03]

The 2 ports are working correctly, heating flow is stone cold, only the hot water flow and the return pipe are getting hot

 

[EvilDrPorkChop]

Get warm or hot? Sounds like you're cylinder isn't the last to be tee'd into the return if your flow from the CH motorised valve isn't hot.

 

[N plumber]

As you said you have system boiler that means you must have main or balanced cold feed into your sealed cylinder. In that case the problem lies on 3 port valve or the programmer. Check your 3 port valve, unless if it's stuck on manual open position. If it's stuck on fully manually open position then you get both hot (radiator and water) at the same time.

 

[mallone655]

As EvilDrPorkChop said cylinder not last t on return

 

[Best]

Piped wrong and there is a loop through rads return caused by one or more rad tee offs on return, with one of those between return to cylinder and boiler.

 

[SimonG]

Reverse return circulation. Incorrectly piped.