connecting underfloor heating to a combi part 2

[@markplumber3635]

Neat work, good use of close coupled tee Top work

[@theghostofsirjohnharveyjon8730]

Nice cross over that nib. That's a once in a lifetime occasion where it goes that right 😉

[@griffithsheating]

Once in a generation mate. That's all my luck used up 🙂

[@Loopyengineeringco]

Am I right in understanding CCT and LLH work only because there's a pump for each half of the circuit? So there's a pump in the boiler, and also a pump on the secondary circuit? Because all can see is the plumbing equivalent of a short, and my brain is struggling to see why it works.

[@griffithsheating]

Yeah CCTs are a pretty abstract concept to get your head around.

[@Jordan-gw8hj]

What does the pump in the boiler do? In this case you’ve got a pump in the boiler an external pump for radiators and a pump for underfloor heating Great video on looking at this job from a practical perspective

[@griffithsheating]

Boiler pump circulates around the close coupled tees under the boiler then separate pumps for each circuit to maintain the correct flow rates and ∆t. Boiler wants dt20 ufh wants dt5 and the heating can run dt10 or whatever you set the pump at

[@Jordan-gw8hj]

@@griffithsheating thanks for explaining. This video with this explanation has greatly improved my confidence with a job Im shortly carrying out. Replacing OV heat only boiler with combi with UFH and rads Thankyou

[@griffithsheating]

@@Jordan-gw8hj doing CCTs for the first time and joining the flow and return together feels very wrong but they work great 👍

[@Jordan-gw8hj]

Programmable stats sending power to the relating individual pump for either rads or UFH on the manifold and also sending a switch live to the boiler? Best way to do it? No zone valves required?

[@griffithsheating]

@@Jordan-gw8hj I just used an RF stat to switch the ufh pump and an RF stat to run the rads. No zone valve bodies but I think I used the zone valve heads as rough arse relays or you get back feeds bringing the ufh pump on and vice versa

[@chrisbrealey1300]

How did you wire the pump on/off for the ufh via the wireless programmer. Thanks

[@griffithsheating]

I think I used a motorized valve head as a kind of relay from memory 🤔

[@chrisbrealey1300]

@@griffithsheating Thanks, quick reply! Yeah job I went to today plumber had only put one motorised valve on heating side so I was scratching my head how this would work without back feeding to ufh pump. Only thing I could think of was installing a relay. Thanks again

[@henrybartlett1986]

Crikey, that was a pain on the pipe run! Nothing worse than inheriting someone else’s job. Did you range rate the boiler?

[@griffithsheating]

It wasn't as bad as it looked to be honest. Yes mate I always try and put a lid on the output and flow temperature where possible. Dead easy to do on the ecotec pros.

[@normanboyes4983]

Nice job bridging the chasm between boiler and manifold- not the easiest of jobs. How did you balance the UFH loops on delta T for each loop? Was/Is there a part 3? Excellent work - lucky customer!😀👍

[@griffithsheating]

I think I calculated it long hand. I went back there just after last winter to do their kitchen and the customer said 'I don't think we needed the underfloor heating it's been just perfect in here without it on' It had been on all winter and they just hadn't realised. So I guess we calculated right 😄

[@normanboyes4983]

@@griffithsheating That’s a brilliant outcome and exactly how UFH should operate. You clearly hit the sweet spot if they thought the floor was off.👍

[@nicodavies1437]

surprised you haven't struggled with flow rates but neat install mate

[@griffithsheating]

That's what the close coupled T does

[@steveyboyXRP]

you not like bending machine

[@griffithsheating]

LoL. Mine bends crooked and ripples 15mm. I need to get a new one but never get round to it....🤠