richo106

I have been having a play with heating over the last week or so, instead of just changing my water temp to 35 deg I changed my weather comp curve so at 5 deg it was 35 deg. This just caused my downstairs to over heat really, when it warmed up it went too hot and then cooled down again rather than a nice constant temp I didn't see much improvement in FF either, only left it for 24 hours due to being too warm downstairs I have been doing some more reading and think i have come to the conclusion that the water temp needs to be at 45 deg to actually produce enough heat output on the plates. For info i have a 12kW Panosonic Aquarea monobloc Its frustrating as the weather comp how i have it set now works perfectly for downstairs (even the mrs is happy!) but upstairs heating is non existent. I have a common 100L buffer tank and common pump for both GF & FF UFH, one (maybe daft) idea i have is to set my weather comp to 45 deg (not sure what other numbers yet haha) and then install a seperate cold water blending valve and pump to GF manifold - would this work you think? I am complete novice when it comes to this so please any ideas/info would be very grateful! In an ideal world i need my FF temp 45 and GF working off the weather comp like it is now not sure that is possible though COP data: Heating (A7/W35): 12.00 kW | COP: 4.80 Heating (A7/W55): 12.00 kW | COP: 3.05 Heating (A–7/W35): 12.00 kW | COP: 2.82 Heating (A–7/W55): 12.00 kW | COP: 2.00 Kind Regards

Hi All I have a Vent Axia Sentinel MVHR, it is only 2 years old but has a very noisy fan! I have managed to get a replacement fan from Vent Axia (see pic) but as over a year old they wouldn't repair it. The noise is now driving me mad so want to get this replaced ASAP Please see attached picture my install in the loft, do all 4 solid ducting inlet/outlets need to be removed? Could it this repair be done just by taking the side off? I am hoping its pretty obvious which fan it is when i take the covers off etc.. I am electrician by trade, how long would this repair hope to take if all goes well? Would it matter if the house doesnt run for MVHR for a day or 2 if I have to do it in evenings? Any advice/information on this would be very helpful Kind Regards

Hi All We are now having the first cold snap since starting this thread. And unfortunately my daughter’s bedroom with door shut is Currently 17.5 degrees! The only thing I have changed so far from last year is not stopped the heating during the expensive period (16.00 - 19.00) I think it’s pretty it’s the installation/lack of pipes that’s the main reason but I now just trying to thinks of ways to help it a little I might change my weather comp to 35 deg at 0 deg (currently -3 or -5 can’t remember exactly ) I will turn my pump to powerful mode to increase l/min on the manifolds is it worth increasing the temperature passed 35 deg or would then it become inefficient? any other ideals would be very grateful

Right after looking on the internet My pump was on proportional power - medium (flashing green) I have now changed this to constant power - highest power (constant orange)

I just turned my GF manifold off and checked the flow rates of the FF one Basically when the downstairs is on its looking approx 24/25 When the downstairs is off its about 35 Is that what people would expect? I will look into the pump settings shorty

Yes I will certainly try 24/7 running, will set this up tonight to see how I go on for the next few days. Will try and monitor temp and energy consumption best I can but not too cold at the minute If this doesn’t make anything difference I’ll defo look at increasing the flow rate, somehow splitting the circuits and installing an additional pump

Yes I can understand the low dT, I checked the temps again this morning and loops ranged between 1-1.8 deg loss, but IR camera was bouncing around a little so hard to be super accurate I will turn off the GF manifold again so the the pump just feeds the FF to see what flow rates I can achieve per loop. currently the ASHP feeds a buffer tank and then pumped from there to both manifolds using a single pump. one thing that I want to try is not shutting my heating off during 4-7 during the expensive period to see if this makes any difference at all. I’ll just run my heating 24/7 on weather comp with thermostats set at 23.5 to stop overheating. do you think this will make much difference cost wise? It takes a large amount of energy to reheat the floors and buffer tank when it heats back up at 7 so hopefully it won’t be too much difference any thoughts on this would be helpful

Did you manage to anything to improve it? Or just manage with it?

Thanks @John Carroll Currently the 11 loops on the manifold have an average flow rate of approx of 2l/m so would that mean total flow rate of approx 22LPM. Is there anything that can be done to increase the dT at all? Guessing that’s to do with install etc Is it as ‘simple’ as splitting the GF and FF circuits and have a pump for each? If the new/separate pump increases flow rate to approx 3 for example. Or would it be better to aim for 4? When I turned the GF Monifold off previously the flow rates did increase to around 3 but even we some tweaking on the flow rate indicators I couldn’t get them To increase passed that

At 9pm I upped my water temp to 35 deg At 11pm I checked the flow and return temps on my FF manifold, average in was 32deg and return 31deg. So averaging around 1 deg heat loss My bathroom tiled floor has increased from 20.5deg to 21 deg from 7pm to 11pm I am not sure where to go next

Update I have borrowed an IR camera to check flow and return temps of the FF manifold The heating turned on at 7pm I have recorded the temps at 7.15pm and 7.45pm, please see attached picture to show my findings There is definitely heat loss but not much I have also IR camera'd the carpeted floor and can see the heat lines, this was around 8pm and the temp of the heat was around 20.2 deg and the 'cold bit' was 19.6 deg There was no of any heat lines on the tiled floor in the bathrooms yet (there is downstairs but appreciate the floor make up is different) For this shows the water is getting round the loops at least One thought i have now is to take it off weather compensation curve and set the water temp to 35 deg, this will make the GF 'bounce off' the thermostats though. I am not sure this will make enough difference on the freezing cold days upstairs though Any other thoughts/ideas on my findings today would be grateful, many thanks

@Nickfromwales I would love to know what step 2 is

I thought i would unscrew all the actuators to see if that would make a difference (not expecting it to) 6.55pm - temp in and out was 21deg (heating been off 3 hours) 7.01pm - temp in was 25 and temp out 21 - also changed over temp gauge to prove working 7.05pm - 23 deg in and out 8pm - 25 deg in and out. For ref the GF manifold temp in 25 deg and and temp out 22 deg Saturday I am going to refill all FF loops just to ensure there is no air in there, once again i am not expecting this to make much difference as there is visible flow on the flow meters (which changes when GF manifold off) but just ticks another thing off

Ok that’s great thank you, guessing this isn’t going to fix all my issues though 😂😂

Are these ok to leave ‘open’ then I am guessing. Do I need to manually purge each loop or if I have air locks will the auto air vents clear it all over a period of time?

They were both quite tight I have done that, tightened them and then I have backed them off 720 deg

I am not sure regarding the flow/return temps before any heat hit it sorry I have just check the flow temps again and no change just the 1 deg diff Please find attached pic of the air vent, to be honest i have to google to see what you meant by that! I have not touched it so any advice what to try I am all ears

Any advice what to try next would be great or what to look out for. If i installed another pump would this improve flow rates on both manifolds? could i even do this? (apologies terrible plumbing knowledge!) Another idea is that i know i turn the heating off between 4 -7 (cosy tariff and expensive period!) could i leave FF running? Sorry all the questions just very determined to hopefully get to the bottom of it one way or another

Update (1) My heating come back on at 7pm (is this cost effective do you think switching it off for the 3 hours?) 7.30pm All FF manifolds flow rate approx 2 on all of them, 25 deg in and 24 out 7.30pm I turned down all GF thermostats so no call for heating. ASHP still running and pump running 7.35pm the flow indicators on my GF were still showing flow even though all call for heat was off, i turned off isolation valve on manifold. All flow rate indicators shot up to show no flow FF manifold flows rates immediately shot up all to around 3 and a couple closer to 4 8pm - flow rates still the higher values - 25 deg in and 24 deg out How long would you leave it like this to see if it actually makes a difference? Would this increased flow make a difference? I have attached a picture of my pump set up, green arrow is to GF manifold approx 4m of pipe and red arrow is FF manifold approx 9m of pipe

I apologies for these daft questions but i can borrow an IR gun from work, what areas should be checking with this? Just floor temps? Or the pipes also? I am going to ask the plumber if he did this, how can i do this now just to ensure there is no air lock? Is it possible to do? I have 2 x manifolds but one common pump, would turning GF off prove that another pump may help or not? Can't seem to get it above 20 deg with cold floors though, tiles feel very cold. Once i shut the doors the temp decreases through the night. I am guessing this doesn't help that i turn my heating off 4 - 7 due to high energy costs

Could i do this by turn the thermostats off?

I will do, in an ideal scenario what will having to FF? My concern is the delta T temps are the same so no heat transfer

yes 16mm Thermrite