PeterW

1 bar at 550m split between 5 properties would be a trickle .... And as you are that far out of the village have you considered the development boundary ..?? That may scupper any plans before you start....

What static and dynamic pressure have you got ..? And have you got a current flow rate on your own supply ..? You can make a crude estimate from those numbers.

Just to add mine turned up yesterday and god is it good stuff ...!!! Had to unstick it from my fingers on a number of occasions ..!!!

The SunAmp replaces the UVC and the PV diverter. It basically uses the PV or E7 electricity to heat a phase change salt - bit like a heat pad with the clicker in that you normally redo in hot water ..? very efficient, and very low losses to the building.

There shouldn’t be an orange hose to the back of the cooker ... All the pipe work inside the house should be copper to a final bayonet flexible hose that is standard on all gas cookers. Outside the property there should be a regulator that has orange flex to it and from there on its copper into the house. That’s the legal requirements.....

Pump should be as warm as the rads. If it’s red hot then it’s blocked somewhere especially if it’s on 3. As @Nickfromwales said - any valves ..??

The issue you will have is size - a small UVC will be 180 litres and the equivalent TS you would want 250 litres to get anything like reasonable storage in it. TS is useful to run UFH too as a buffer - if you’re not having any wet heating then I can’t see any benefit to a TS other than you tend to heat them hotter which means more PV capacity. In in your instance I would very seriously consider the SunAmp - check out @JSHarris and @TerryE blogs as that will give you everything you need in something the size of an undercounted fridge with low losses.

Straight away - you should use copper olives and a decent insert on the pipe but if it’s not tight you will see straight away ...

No issue with using pushfit plastic on copper - it’s copper compression on plastic that can cause problems if you don’t get a meticulous joint.

Ok ... unless you have a particularly difficult plot, or are building something very special, you can get £1000/m2 without much effort and below that if you do a lot of the grunt work yourself. Do not be put off by builder and architect quotes that are usually wildly inaccurate - do your own sums.

Need a photo of the black box on the pump @Dee

Worth putting the filter in before a clean down though @Nickfromwales as if the X800 does its job it will clog up the HeX on the boiler...? @Dee I would fit a Wilo Pico or similar as that will see another good 8-10 years on the pump.

Have a read of Caliwags blog on this site - some thought provoking posts about design ..! And welcome...!!

@Dee Pump is shagged by the sounds of it. Get a new pump, or turn the current one up to max and do the test with the rads again. Sounds like it can’t circulate to all the rads properly. Have you got a Magnaclean in the boiler return flow ..?? That would help you see how much crud in the system and also re-dose the inhibitor. May be worth putting one in then dosing with X400 System cleaner and trying again ... one rad at a time ..! And if you can’t work the rads out then write on each one with dry wipe marker and it means you can just rub it off when you’re done ... TMV pins - are they loose or do they actually move up and down ..??

They are rebadged Chinese units that aren’t great - you can get similar on eBay for £129 delivered ...

Hep2O all the way - if you do have any copper that needs a compression then use something like T-2 or one of the non setting PTFE pastes

Got any pics ...?? Really considering this now ..!

I’ve got a Dymo from Amazon - less than £20 I think delivered. Only replaced the old one as the batteries leaked into it !

How big is the room though..? Is it a new build ..? At 100mm spacing that’s only a 3x4m room so won’t need lots of heating - running it off one single unit on the rad circuit may be quicker. You may not need a pump if you do it right however if there is a pump in the boiler you have to work out how to control it by both stats. A new controller with two time programmes may be a start.

How well insulated is the room with UFH ...?? And what size is it ..? For single rooms you’re sometimes better using this sort of thing off the rad circuit https://www.underfloorheatingsupply.co.uk/Single-room-thermostatic-valve?gclid=EAIaIQobChMI7s6RlYHs1gIVERIbCh16YgGXEAQYASABEgJVEPD_BwE

So you will need to watch this one carefully or the UFH will overshoot big style. It’s about the only situation you want an undersized boiler too ..! You can use a 2 port to isolate the UFH but you need to know if the boiler has a separate pump or if it’s in the boiler itself ..?

You could get away with just changing the heads if the plungers still work. Take them off and give a squirt of WD40 and see if they move up and down. To balance you need to know the order in which they heat up - do you know the route from boiler to boiler ..?

That tells me that the TRVs don’t work .... isolate the rad with both TRV and lockshield off. It shouldn’t get hot at all.

I was advised on here I think to go for twin Henley blocks rather than the double decker ones as if the casing cracks you’ve got a 100a nightmare waiting to happen ...

What software has produced that as I would be surprised that all the condensation rates would be zero.