Warm radiators when heating is off on indirect system

[GKM]

Hello, I have just moved my hot water tank up to the loft, it is an indirect system and I seem to have two issues. the water now seems to take an age to warm up and when it does some radiators upstairs become warm.

Any tips would be good

 

[seco services]

is the mot valve working properly

 

[gaspro1981]

is this a vented or pressurised system

 

[GKM]

This is a vented system, to be honest not 100% sure of the operation. I know the pump circulates the water for the central heating which also goes through the coil in the tank. I am assuming that when the heating is off the hot water reaches the hot tank by gravity (am I correct ?) maybe it is taking longer to heat up as it has further to travel. my thought was that as the tank got hot there was some residue heat around the coil which was transferring down to one or two rads upstairs.

Only a theory but if someone could tell me exactly how this works if I am wrong I may understand my problems better.

 

[seco services]

so your not sure if its fully pumped or gravity hot water ?
have you one of these

or any of these

 

[GKM]

Gravity fed I am fairly sure, only pump is for central heating.