Location of non return valves

[Ukdodger]

Hi, Should I have a non return valve on the heating and another on the hot water. I have a two (separate) pump system and there is no non return valve on the hot water. Only on the heating. What's confusing me is it's been working for fifteen years and I dont recall the hot water getting hot when only heating is being used. I should add that as one pump activates the other is wired to turn off. So turning on the hot water will stop the heating pump. It's hot water prefered. Any advice more than welcome. Thanks.

 

[Best]

Depends on what way your boiler is piped.
Sometimes a check valve is to prevent some unwanted gravity circulation

 

[Ukdodger]

Depends on what way your boiler is piped.
Sometimes a check valve is to prevent some unwanted gravity circulation

Thanks but I dont think gravity is a problem. I cant see why water being pulled out of the boiler flow for the heating wouldnt do the same for the hot water as both flows are teed and both returns are teed at the boiler.

 

[SimonG]

So do you have 2 two port valves as well as the pumps?

 

[gassafe]

Have you actually got a fault or just asking?