Witzend said:
The return from the cylinder and the CH expansion feed pipe is on the return pipe to the boiler LHS (under floor). The pump is after the bypass pipe on the RHS flow side of the boiler (under floor).Is this wrong?
I contacted Hep-Heating again and asked Can you tell me whether it would cause problems if
1. the central heating expansion tank refill pipe is connected into the
system just before it returns to the boiler (not before the pump on the
flow pipe as recommended in the Micron install. guide)
2. The bypass pipe is situated about 2 feet away from the boiler, not 2
metres as per diagram in installation manual.
The pipe is also 15mm not 22mm as instructed.
I realised after sending the email that the 2 metres was probably the length of the pipework and not the actual distance from the boiler but wot the hell...I'm a girly.
Their reply was "I can confirm that the close coupled vent and
cold feed is the preferred option. Putting the cold feed on the return
would be likely to cause problems where either there was insufficient
static head or the system resistance was unusually high. Moreover, the
bypass should be 22mm and the total bypass length should be a minimum of 4m"