marshian

It’s meant well if you are lost on the roads sat nav will get you home - but if you ignore it and decide you know better you can end up lost. the contributions here regarding zoots ASHP are well meaning so think of it as sat nav directions…,.. zoot can chose to ignore it……

It means literally - want a warm house in the day you need to allow it to trickle heat in 24/7 Want a cold bedroom - turn the bloody rad off overnight and back on in the morning

Sat nav works for roads....... ASHP not so much

Exactly........................................

If you are using low heat levels to cover the heat being lost - you run the heating 24/7 - you can add a little setback if you want to bedrooms at night or fit trvs and cap the bedroom temps that way but the issue with setbacks is you need to run a higher temp to recover from the setback period My house bedrooms are at 18, living areas 20 and bathrooms 21 - all other areas are between 16 and 19 house is far more comfortable than heating am and PM in timed slots and the cost difference for me is an extra £60 a year - I’m happy to pay that because I can do that on a good night on the beer!!!!

I can go along with that I didn't want to go down the route of explaining what ON means for my house but since you've pulled me up on the word ON Outside temp sensor tells the boiler how cold it is - based on this temp the weather compensation curve sets the flow temp At outside temps below minus 2.5 the boiler pretty much consumes energy all the time at a rate of 4 kWh (so peak consumption when it's that temp outside in a day is 96 kWh (plus a 4 to 5 kWh for HW) This means my peak cost is £5 a day (100 * £0.05) When it's not bloody cold the boiler cycles - puts in some heat "on a burn" - circuit cools down "on a coast" Depending on the outside temp the burn can be as little as 20 mins or as much as 60 mins and the coast can be as little as 10 mins or as long as 3 hours - All I am trying to do is replace the heat lost and that heat lost is directly related to the difference between warm inside house and colder outside house - I'm not trying to heat the house....... It is a comfortable temp all the time because the boiler is putting back what the house is losing PS I have no TRV intervention - they are there as absolute room temp limiters in the event of solar gain Each rad is sized to the room heat loss No UFH (all rads) Flow temps range from 25 deg to 33 deg C - no rad ever feels warm!!!

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Don't drag me into this madness @-rick- To the OP My heating goes on in Sept and it get turned off in May once it is on it's on 24/7 - no setbacks at night - no comfort setting in the day time or any time - it's just on on permanently on - never turned off it's just ON ON Why? because as soon as the outside air temp drops below an average of 16.5 deg C this house needs a heat input (it might not need a lot at the start but it needs some so it gets some) - if I let it cool down in the winter it can take several days to get back to temperature and I'll pretty much consume the same amount of energy as if I'd left the heating on all the time so I don't because it's pointless. You are trying to heat a house with short bursts of heat from a heating system that is better suited to long low and slow - sorry but that's frankly madness................. I'm out.

I'm trying to help a friend with mental health issues - he's been living on his own in a house with no heating working over winter (I wasn't aware of this till I visited) - surprising how quickly he's gone downhill - it's a 25 year old house but no real fire or wood burner to revert to like an older property. when I visited it was actually warmer outside than inside. I'm not actually sure what is wrong with it but I'm going to try to get it fixed (providing the gas hasn't been cut off which is always a possibility!!)

I'm out - Late Shift

That's what I would be doing - a thin layer of foil insulation isn't going to have much impact on heat loss on a suspended ground floor

Really depends on cyl size and how much has been depleted - I was taking worst case scenario in a house with 5 people I have 117 Litre Cyl (2 people) 4 showers a day (two morning and two evening sees the top of the tank at 38 and the bottom at 12 - I can guarantee you that the average cyl temperature is not 26 Deg C (best guess would be 10 L at 38 and 107 litres at 12 would be an avg temp if you mixed it of 16 Deg) @Bigdeadbadger would be in more HW trouble if his three kids were girls

Mine gets that low every damn day.............. Cold water in is less than 12 Deg C right now

If my mental maths is right I'd say your water heating is going to need more poke than your space heating so get a boiler which will go as low as possible for space heating (Viessmann 200 will go down to 2kWh) Then size the boiler to to recharge a 400 litre cylinder with a heat pump coil in the shortest time possible (so 400 litres from 20 to 55 needs 17 kWh of energy) to do that in ~30 mins would need a boiler capable of throwing 32 kW at it)

Can always "upgrade" to ASHP later?? What do you think your heat loss will be at design temp because that's going to determine what min boiler output you need and the HW cyl size and HW demand is going to determine the maximum boiler output? (unless HW is lower than the heat loss)