@jamespa Ah, really?  Maybe we’re not as well insulated as we thought.

I am definitely going to follow the more logical approach you outlined. Current setup is just me dropping the flow temp after being alarmed at the amount of electricity we’re using.

I tried changing the flow temp to 36 initially and found the thermostats reporting that the temperature was dropping in some rooms so I’ve upped it to 38.  

@sandman1600 if your house is 130m2 and you have a 14kw mitshi machine....... I would be staggered if it wasn't oversized. that's 107w/m2. that's a really really poorly insulated house with holes in the windows 

Posted by: @davidnolan22

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@sandman1600 

Your problem will be the minimum output of the 14kw heat pump might be not far from your heat loss in cold weather,

I'm sorry to sound thick but what does this mean? 

As for the rest of your advice, thank you. Definitely makes sense that it may take time to warm up the fabric of the house. I’d kind of considered that the concrete floor would take time to heat but yeah, I’d not really considered the whole property absorbing that heat. Thanks. 

@davidnolan22 Oh wow. Starting to sweat that we have been sold an inappropriate heat pump.

Posted by: @sandman1600

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@davidnolan22 Oh wow. Starting to sweat that we have been sold an inappropriate heat pump.

Based on the numbers I think its likely its oversized.  Not a disaster but it means it will probably cycle on and off a lot.  If does prove to be oversized (difficult to tell until you have it working without influence from external controls and also some monitoring) and you have a big enough slab you may find you can cost effectively batch heat the slab during cheap rate periods (much like storage heaters).  It may take some experimentation but for sure you are going to save money relative to operating at 55C flow temperature!

I’d also listen to James, he gives good advice.

i didn’t mean to concern you, and I’ve seen the 14kw zubadan modulate quite low on heat pump monitor. 

but keep patience with it. It’s take me an entire winter to get a grasp of my system. And you’ll likely run out of time soon and it will get too warm outside 

Posted by: @gary

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@davidnolan22 good spot, that should probably be ideally removed not needed for a heat pump.

Needs to be set so it doesn't do anything if possible.

Sorry I totally overlooked the comment about the Blending Valve. There’s one on each manifold and they’re set to a high temperature… 52 degreesish.

The only option I have is to turn them right down or right up to max. 

I’m assuming max would be the best option?

I’ve set the weather curve to -3 and 45 initially.

Looking at reports (obsessively at 5am this morning) it’s mostly stayed at a flat 40 degrees approximately but then its wobbled between 2am and 4am and its flat again for the last hour but falling right now.

I’m going to continue adjusting the curve to see how low I can get it but temperature overnight in the various room thermostats seems to have been kept constant at around the levels we’d like so I’m concerned that reducing them will cause the room temperature to drop too much but we’ll see. 

csn you post the pictures again, but just have flow temperature and return temperature showing.

this is the important temp in the primary flow snd return. Do you have a buffer tank? Or low loss header? 

snd do you have the UFH design with pipe size and spacing? 

and yes, set blending valves to max. 

the wobbles are the unit defrosting I think, but need return temp to be sure

@davidnolan22 Apologies. I didn’t realise you could select which options were showing on the graph. 🤦🏻‍♂️

I’ve attached them below. 

The UFH uses 12mm pipe on an overlay board with 150mm spacing. I’ve attached a photo of one of the rooms mid progress for reference.

We do have separate buffer tanks for the hot water and UFH  

@sandman1600 

does it have a finishing screed over it?

do you know how to get the flow rate through the machine from the FT6 control panel?

do you happen to have a temp gun or probe and would you be confident measuring the water temp at the manifold of system side of the buffer? 

how many pump and runs do you have off the buffer?

Posted by: @davidnolan22

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@sandman1600 

does it have a finishing screed over it?

do you know how to get the flow rate through the machine from the FT6 control panel?

do you happen to have a temp gun or probe and would you be confident measuring the water temp at the manifold of system side of the buffer? 

how many pump and runs do you have off the buffer?

The pipes and overlay board were tiled on directly as per Polypipe recommendation. 

We’ve been given an FTC7 controller. I’ll take another look but when I checked originally all flow temp indication seems to disappear when we turn on weather compensation. 

I have a laser temperature gun. If it’s just a case of aiming it at the right pipe, I can do that. When I figure out what the right pipe is.

I’ll take a look at the buffer tanks and see if I can figure out what’s what. We have a white one and a red one and I think the red one was for the UFH. 

Sorry for the lack of clarity. There’s a reason why I thought this was best left to the “experts” that installed it.   Clearly a mistake  

Most installers I think want to do a good job.

im struggling to getting head around a 14kw unit for a smallish bungalow that I can see insulation has been put into. But the flow rate through the machine will give you a good indication on how much power the unit is giving out. You won’t find that in the main screen.  ite I’m settings, running information, then code 540. It will display a number. 

was the UFH installed initially into a gas system? You happen you know the output per m2 of that UFH system.