Is this OK? Service bypass for radiators

21 Jul 2012
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New Hampshire
United Kingdom
Hi All,

I am remodelling a room in my house that has baseboard radiators. I have removed them, and am replacing them with wall-mounted radiators of what I think is the right BTU rating (more on that later) but what I am wondering is this:

The system is piped primary/secondary. The secondary consists of three zones, all in their own monoflow loop. Zone one is the off-boiler water heater. Zone two is the upstairs zone, zone three is the zone I am replacing some of the baseboard rads in.

This zone three was all monoflow baseboard - just one pipe from the circulator through all the baseboard in one loop.

The part of the baseboard I am replacing with rads I will (correct me if wrong) pipe with a monoflow tee branching off into the rad, the return comes back to a regular tee. In other words, a bog-standard parallel loop with monoflow tee on the input.

What I am wondering about is this: If I were to put full-port ball valves on the send and return portions after the tees, and *another* parallel pipe between them with a ball valve in the middle, I would then have a service loop, right? In other words, with the send/return valves open and the loop valve closed, the rad functions as normal, but with the send/return closed and the loop open, it would bypass the radiator with a pipe to return full flow from the monoflow tee input.

Make sense? Or is there a reason that this would interfere with proper flow somehow?

Thanks in advance,


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This is a UK based forum and we do things differently on this side of the Pond!

May I suggest you post your question on Heating Help, which is a USA based forum.

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