Underfloor heating system not very efficient - what can i do
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Most of us in the trade refuse to have a smart meter. I'm with OVO (and previously Sainsburys/BG) and they employ the most useless inept software teams.
The absolute dross of the programming world seem to work for these companies. I've found so many bugs in their websites and I suspect the smart meter readings are no better.
I would read the litres gas usage from the display and just confirm your bills are correct. If you haven't the meter manual post a pic of the meter and we'll dig out the details to put it in litres mode.
My cylinder is on 24/7...the minimal extra heat loss contributes to space heating for 8 months of the year so there's virtually nill savings to be made having a schedule....hot water usage is key.
The absolute dross of the programming world seem to work for these companies. I've found so many bugs in their websites and I suspect the smart meter readings are no better.
I would read the litres gas usage from the display and just confirm your bills are correct. If you haven't the meter manual post a pic of the meter and we'll dig out the details to put it in litres mode.
My cylinder is on 24/7...the minimal extra heat loss contributes to space heating for 8 months of the year so there's virtually nill savings to be made having a schedule....hot water usage is key.
It's different, as we had a combi then, radiators only on a hefty 34kw boiler, and floor space was much less. On average then, gas bills £50 a month.
Floor area about 80sqm not 100sqm.
Zone A = 14sqm
zone B = 10sqm
Zone C and D = 28sqm
Zone E= 25sqm
To put it into perspective, zone D and E are new and wasn't part of the house when we had a combi boiler. At that point, we had a radiator in zone A, Zone B and zone C and the bottom part of zone B used to be the only bathroom in the house.
The worst part was when the installers mixed up the flow and return pipes, sometimes gas bill would be £400 a month, since that got resolved nothing like those figures but I still feel something isn't quite right, still feel as though there is another optimization lever that can be turned on. Certain things I cannot do, but getting advice on what the temp should be and schedule etc would be helpful.
From what I understand, underfloor heating can run in a circulation mode whereby it pumps water around the circuit without needing the boiler to heat the water during certain periods, how true is this ?
Please help me here, when you say 24/7 do you mean that its burning gas 24/7. Our hot water usage is minimal, only showers + hand washing + kitchen usage. Thats it.
What temp do you set the stat on the cylinder do ?
Do you mean your unvented cylinder ?
In terms of how to set the underfloor, what do you suggest ?
Below is my gas meter
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If i understand this well, it sounds like your cylinder is in a airing cupboard or a room which is also being heated from the heat loss from the cylinder. In my case, the cylinder is in the garage as that was the only space to put it. It was either there or we have no utility room internally.
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I don't believe your gas bill was £50 pm for the same period.
Some thoughts:
1) perhaps £50pm is summer, not winter.
2) you've doubled your heating area.
3) Combi showers use less water and thus less heat than pumped showers.
5 people using a pumped shower ain't cheap. Buy a shower timer.
I can't help but think there isn't a big problem here. Sounds like you've gone from a Ford Focus to a Ferrari and are complaining about mpg without seeing the obvious.
Some thoughts:
1) perhaps £50pm is summer, not winter.
2) you've doubled your heating area.
3) Combi showers use less water and thus less heat than pumped showers.
5 people using a pumped shower ain't cheap. Buy a shower timer.
I can't help but think there isn't a big problem here. Sounds like you've gone from a Ford Focus to a Ferrari and are complaining about mpg without seeing the obvious.
My cylinder can demand 24/7...in realiality my 120 litre does a single long burn (perhaps 20 mins) and a few top-ups through the day/night.
Sorry forgot...your cylinder will be heating the garage so it would be a little beneficial to set the timer to give hot water as and when necessary.
Unvented cylinders can often be more efficient as the calorifier can dissipate a higher kW than most vented cylinders leading to less boiler cycling.
I've known teenagers to get through a 220 litre cylinder in a single shower.
Luckily for you that's one of the easier smart meters...just wake it up and it displays the gas reading.
Have you got all the design documentation for the underfloor system?
Sorry forgot...your cylinder will be heating the garage so it would be a little beneficial to set the timer to give hot water as and when necessary.
Unvented cylinders can often be more efficient as the calorifier can dissipate a higher kW than most vented cylinders leading to less boiler cycling.
I've known teenagers to get through a 220 litre cylinder in a single shower.
Luckily for you that's one of the easier smart meters...just wake it up and it displays the gas reading.
Have you got all the design documentation for the underfloor system?
In terms of design for the UFH system, all I have is a diagram circuit design for the various zones and a bunch of manuals for the stats and manifold/pump etc. Nothing more unfortunately.
The circuit design is the diagram on the first page which shows the various zones, the flow valves pictured on page 1 doesn't look like its working, when i watch youtube videos you can control this up/down and you see the gauge going up/down. With mine, the water is dirty, even when i drained out the system thinking it would be clear, it wasn't.
I also think the system needs to be balanced properly such the zones furthest away can have their output increased, and the zones closer to the manifold can have their output reduced. I could be wrong here, as i am not an engineer. Just based off research.
I should also point out, when the UFH is turned on for 2hrs using the hold function, at the moment its warm enough till midnight. The zones closest to the biggest heat loss areas (front door and bifold door by kitchen) are usually the ones that need topping up, but this is what I would expect.
Running your underfloor, as has been mentioned you don't run underfloor like a radiator system.
You should typically run the underfloor a maximum of 4c between desired room temperature and backset temperature.
Without seeing design criteria difficult to be precise but try a blender temperature of say 50c as you have a 70mm screed (optimum is 65mm) with 200 mm pipe spacing you should achieve a output of 76.3 W/m2 with a floor temperature of 27.c
So overall you underfloor should be putting out just over 6 KW.
You should typically run the underfloor a maximum of 4c between desired room temperature and backset temperature.
Without seeing design criteria difficult to be precise but try a blender temperature of say 50c as you have a 70mm screed (optimum is 65mm) with 200 mm pipe spacing you should achieve a output of 76.3 W/m2 with a floor temperature of 27.c
So overall you underfloor should be putting out just over 6 KW.
Blender changed to 50c today, still about 50kw of gas used in 2hrs.
The desired room temp is 21c, what temp should i set the stat ?
Any suggestion as to the schedule, I will need pointers here please. For example 7am - 7pm set it to run at 19c, and then by 7pm, backset to 15c ?
I am not joking, see for yourself.
Morning and just now.
Just now
The reason why i came on here was not to moan about having a ferrari of a heating system, its an uncommon setup and sadly there is no other household locally that i can compare with, hence the reason for asking if this is as expected. If it is then fine, if its not it sets the scene for the conversation with the engineer that i will call in.
One other observation is that when the boiler goes and stops working, the manifold pump stops also. Is this normal ?
You just opened my eyes here, that's 7.5hrs difference and lets say 55KW used. So does that mean that even though the boiler was on for 2hrs, it was consuming gas at the rate of approx 7.5kw/hr ? Please help me understand it.DIYnot Local
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