Just planning some significant upgrades to my central heating system, and would appreciate some guidance from experts.
1500s large 2-storey stone house with a 1990s extension. 3yr old Warmflow 33kw condensing oil boiler in an external boilerhouse running a vented s-plan pumped system for DHW unvented cylinder and vented central heating system with a feed/expansion tank in loft. Approx 15 rads in total after the upgrades. The whole house works as a single zone (sleeping and living accommodation is all over the place and there are no easy/sensible zones to create). I'm planning a smart thermostat with smart TRVs in some rooms after the upgrade, so will effectively be able to zone the areas I want this way.
The extension had CH installed when built - 28mm flow and return pipes with manifolds and 10mm microbore to the 4 rads there. Works fine.
The "old" part of the house has a b*ggers muddle of single-pipe system and effectively I'm starting again but reusing existing rads and some of the pipework where I can. Access through three foot thick walls and with no ceiling voids and huge chimneys is challenging in places.
So - I'm planning on creating a single loop for the flow and return for both parts of the house - in reality extending the existing 28mm F/R from the extension to feed the core of the old house too. I'll then run 15mm tails to the rads, or possible a couple of rads at a time.
Lots of preamble - I hope it's helpful.
Here's the questions. They may seem odd, but are driven by the difficult access issues I have getting from boiler room into the old house. They are also driven by the cost of installation (I am just a poor (but handy) farmer)).
1) Does the flow/return need to be a single loop? Could I branch it after the CH motorised valve after the pump into 2 loops - a new branch for the old house and the existing loop for the extension?
2) If I can branch it, would it be ok for the loop to the new house to be in 22mm and the existing to the extension in 28mm? What issues would that cause?
3) If I can't branch it, can I use 22mm and 28mm on the same flow/return loop? And if I can't does it matter if the 28mm or 22mm section is first on the circuit. Logically I would think the 28mm should come first... but thought I'd check as I could do either.
4) I suspect given the size of the system, the best answer is a single 28m flow/return loop for the whole house - but installation-wise this would be the hardest for me to do.
I hope that makes sense, and thanks very much for reading. Grateful for any advice or pointers to more reading.
Robin
1500s large 2-storey stone house with a 1990s extension. 3yr old Warmflow 33kw condensing oil boiler in an external boilerhouse running a vented s-plan pumped system for DHW unvented cylinder and vented central heating system with a feed/expansion tank in loft. Approx 15 rads in total after the upgrades. The whole house works as a single zone (sleeping and living accommodation is all over the place and there are no easy/sensible zones to create). I'm planning a smart thermostat with smart TRVs in some rooms after the upgrade, so will effectively be able to zone the areas I want this way.
The extension had CH installed when built - 28mm flow and return pipes with manifolds and 10mm microbore to the 4 rads there. Works fine.
The "old" part of the house has a b*ggers muddle of single-pipe system and effectively I'm starting again but reusing existing rads and some of the pipework where I can. Access through three foot thick walls and with no ceiling voids and huge chimneys is challenging in places.
So - I'm planning on creating a single loop for the flow and return for both parts of the house - in reality extending the existing 28mm F/R from the extension to feed the core of the old house too. I'll then run 15mm tails to the rads, or possible a couple of rads at a time.
Lots of preamble - I hope it's helpful.
Here's the questions. They may seem odd, but are driven by the difficult access issues I have getting from boiler room into the old house. They are also driven by the cost of installation (I am just a poor (but handy) farmer)).
1) Does the flow/return need to be a single loop? Could I branch it after the CH motorised valve after the pump into 2 loops - a new branch for the old house and the existing loop for the extension?
2) If I can branch it, would it be ok for the loop to the new house to be in 22mm and the existing to the extension in 28mm? What issues would that cause?
3) If I can't branch it, can I use 22mm and 28mm on the same flow/return loop? And if I can't does it matter if the 28mm or 22mm section is first on the circuit. Logically I would think the 28mm should come first... but thought I'd check as I could do either.
4) I suspect given the size of the system, the best answer is a single 28m flow/return loop for the whole house - but installation-wise this would be the hardest for me to do.
I hope that makes sense, and thanks very much for reading. Grateful for any advice or pointers to more reading.
Robin
