Heat Sink Radiator

[Mickjohn]

I don't understand why you would need to rip up your floor boards to install an automatic bypass valve. They're usually installed within about a metre of the boiler so unless you have a very short pipe run from the boiler before the pipes disappear into the floor installing an ABV shouldn't be a problem.

Hi thank you for your reply an earlier post says the automatic by pass valve should be on the other side of the pump from the boiler and my pump is about 7M away from boiler under the floor boards.

Mick

[Mickjohn]

Here is a link to why a bypass is installed.
https://www.youtube.com/watch?v=7sp78lBoSPw&t=93s

Hi many thanks I think I understand now....

Mick

[DBMandrake]

Hi thank you for your reply an earlier post says the automatic by pass valve should be on the other side of the pump from the boiler and my pump is about 7M away from boiler under the floor boards.

Ok. Yes it has to go between the output side of the pump and the return line. Strange to have the pump under the floor boards, I've never heard of such a thing...

[bruce_miranda]

Isn't the pump considered a replaceable part of the heating system and thus must be accessible. Installing it under the floorboards has got to be just asking for trouble.

[DBMandrake]

Isn't the pump considered a replaceable part of the heating system and thus must be accessible. Installing it under the floorboards has got to be just asking for trouble.

They also get very hot even when out in the open (flow temperature plus power dissipation of the pump) so I would imagine that having it trapped under floor boards with no way to cool properly would lead to overheating and shortened life.

Also, how is the system bled properly if it has to be drained and refilled ? Part of the refilling and bleeding process is to loosen the bleed screw on the front of the pump...

[Mickjohn]

Hi
All I can tell you is that the system was installed in 1978, the first grundfoss pump was changed in 2003 and second grundfoss one is still going strong, I have drained system probably about 4 times and never had any problems either draining or refilling.

Mick