V
vdesilva
I am in the process of re-designing a fully pumped open-vented CH and HW system that is operated by a 3 -position valve, TRVs on all radiators except the towel rails, close coupled boiler, three channel controller and thermostats.
There are two things under consideration:
1. using a closed un-vented system and installing an expansion tank,
2. installing the expansion tank in the loft along with the pump.
The intention is to do a minimum of re-plumbing by keeping the 3-position valve, HW tank in the linned cupboard where it is now, keeping the system boiler (but removing the close coupled feed and expansion), on the ground floor but re-position the pump and expansion tank in the loft which is 3 storeys up.
The design consideration is; if the positioning of pump and expansion tank is in the loft, will it create a low enough partial pressure for air dissolved in the water to escape and collect at the highest point of the circuit, and create an air lock?
Thank you for your help in advance
There are two things under consideration:
1. using a closed un-vented system and installing an expansion tank,
2. installing the expansion tank in the loft along with the pump.
The intention is to do a minimum of re-plumbing by keeping the 3-position valve, HW tank in the linned cupboard where it is now, keeping the system boiler (but removing the close coupled feed and expansion), on the ground floor but re-position the pump and expansion tank in the loft which is 3 storeys up.
The design consideration is; if the positioning of pump and expansion tank is in the loft, will it create a low enough partial pressure for air dissolved in the water to escape and collect at the highest point of the circuit, and create an air lock?
Thank you for your help in advance
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