My (rotten) ASHP. Update.

[zoothorn]

@PeterW Ok I'll ramp up the temp later.. but how this can be at all conclusive, just doing it on one occasion, is strange to me (and what else I could possibly say other than 'the rad & therefore the room gets hotter', Ive no idea: am I expected to be noting the time it takes to reach a particular temp or something? taking a note of outside temp too? repeating it on at least 2 days with a similar outside temp difference-?).

 

But what else could it plausibly be? this rads/ room temp discrepency I find one morning to the next, with the outside temp different? you say it 'could be one of many' things other than its temp compensation off kilter..

[zoothorn]

Ramped up to 25* at 6pm (been at 18* all day. Im in my kitchen, hat & coat on, cold nose & legs. This bloody house is absurdly cold! nothing to do with the system).

 

What am I meant to be telling here-?

[zoothorn]

@PeterW ok so I ramped it up to 25* at 6pm. 50mins ago. Outside temp 5.5*. All day its been set to 18*.

 

What would you expect me to find at the rads by now? (is that a legitimate Q?)

[PeterW]

What is the temperature showing on the controller ..?

 

And none of the rads have thermostatic valves do they..??

[zoothorn]

1 minute ago, PeterW said:

What is the temperature showing on the controller ..?

 

And none of the rads have thermostatic valves do they..??

 

 

No trv's (thank god- hateful things). Its showing 19*.

[PeterW]

Rads are ..?? Warm..? Hot..? Cool..? All the same ..?

[zoothorn]

2 minutes ago, PeterW said:

Rads are ..?? Warm..? Hot..? Cool..? All the same ..?

 

Rads mostly fairly-hot, still just coming up to temp as some still cold-warm at btm: so I'd say takes 2 hrs (even with system on all day doing 18*) to get them all fully up to speed (another hour to get rooms warming 9pm, another hour to get rooms nicely warm.. prolly.. but had gone off at 9!).

 

Afaik they only go to fairly-hot @ max.

 

Now, whether this has taken longer tonight -it seems so- I'm not sure.. but I'm bloody cold is all I know!

[PeterW]

Is there a plate / label on the outside unit that tells you the output ..? Should say something like 5kW or 8kW

 

Do all the rads get warm at the same time or do they get warm in a certain order ..??

[zoothorn]

4 minutes ago, PeterW said:

Is there a plate / label on the outside unit that tells you the output ..? Should say something like 5kW or 8kW

 

Do all the rads get warm at the same time or do they get warm in a certain order ..??

 

I know its a 7.5kW Peter. I'd say they all get warm same, you'd expect the 1st in the queue to happen a bit before, as I find.

 

Rads btms are all cold-warm, top you could say only warm now/ defo going down in temp from before. House isn't warm at all. Bathroom is cold, kitchen cold, I'm still in wooly hat cold nose, feet, legs very nippy. Pretty infuriating considering how much I'm spending if its been on alot since 7.30am & I'm just never getting warm. Actually its almost pointless.

 

Temp 19.5*

[zoothorn]

Had to put fan heater on in kitchen, as usual, near flat out too/ only way I can get warm. This house is an absolute nightmare- never known any house like it. I thought this CH would be what I needed, but won't be able to do a gnat's fart in january at this rate, totally pointless to have it on.

 

Rads' sides all remain cold. Depressing.

[PeterW]

7.5kw is the size of three fan heaters. That’s not that big to be honest. It will cost about 50-60p an hour to run I reckon depending on your tariff. 
 

Feet and legs cold would indicate draughts from under doors etc. Think about getting some draught excluders for door bottoms. 
 

I would be tempted to set the temperature on the programmer to 22c and move it into the kitchen (assuming it’s only clipped on the wall) and see what happens. 

[zoothorn]

2 minutes ago, PeterW said:

7.5kw is the size of three fan heaters. That’s not that big to be honest. It will cost about 50-60p an hour to run I reckon depending on your tariff. 
 

Feet and legs cold would indicate draughts from under doors etc. Think about getting some draught excluders for door bottoms. 
 

I would be tempted to set the temperature on the programmer to 22c and move it into the kitchen (assuming it’s only clipped on the wall) and see what happens. 

 

Crikey that's gonna add up- if its on say 8 hrs a day, call it £30 a week/ £120 a month, so I can't possibly even afford it.

 

I have good seals on door btms/ I plugged every nook on 1st winter/ everything. Its just coming up from floor Peter, you can just feel it is (no insulation, slab on ground) and in thru walls (no insulation, 2 brick courses): its not the old part of house too/ its worse. The bathroom adjacent to kitchen, is even colder: even with rad on, plus fan heater on, you stand in shower & get blasted by -cold- air.. the fan's heat just goes by time it gets to you! And that's a mild day (middle of feb, shower's unuseable you're just too cold getting in & out).

 

If I move controller to kitchen, trouble is it'll rarely get up above 19*, meaning it'll just be on almost continually.

 

Currently 20* almost time to go off. House not warm.

 

 

[Onoff]

Just now, zoothorn said:

 

Crikey that's gonna add up- if its on say 8 hrs a day, call it £30 a week/ £120 a month, so I can't possibly even afford it.

 

I have good seals on door btms/ I plugged every nook on 1st winter/ everything. Its just coming up from floor Peter, you can just feel it is (no insulation, slab on ground) and in thru walls (no insulation, 2 brick courses): its not the old part of house too/ its worse. The bathroom adjacent to kitchen, is even colder: even with rad on, plus fan heater on, you stand in shower & get blasted by -cold- air.. the fan's heat just goes by time it gets to you! And that's a mild day (middle of feb, shower's unuseable you're just too cold getting in & out).

 

If I move controller to kitchen, trouble is it'll rarely get up above 19*, meaning it'll just be on almost continually.

 

Currently 20* almost time to go off. House not warm.

 

 

 

I'll raise you 11degC in my bathroom when it's really cold. 

[PeterW]

That’s 5 months of the year, but for the remainder it will be less so will even out. 

[zoothorn]

18 minutes ago, PeterW said:

That’s 5 months of the year, but for the remainder it will be less so will even out. 

 

The remainder.. it'll be off, or rather just HW if that's what you mean. But I can only do this CH (as was ever the intention) Am, due to cost. So to not be able to have it start until I wake (noise) & take 2 hrs to get up to speed so I'm cold AM = I'm never getting any benefit from it. Very frustrating. I've only got it @ 18* during day & on in the evenings as a luxury/ new system I'm treating myself. Its going to default mode next year,  just on 7.30 to 9am.

 

The only good offset, is that my old immersion tank with its wobbly top etc, might have been so inneficient as to have been costly.

 

The other good thing is my workshop, very low ceiling the reason clearly, can actually get warm.. but in the least room I need it. Room above is alarmingly not getting warm really/ huge great rad in there, not noticed any nice comfortable warmth like below in workshop.. & half the reason I built extention, was to have a hunker-down room bc the house is so unbearablly cold.

[dpmiller]

and it won't be at full chat all 8 hours.

[SteamyTea]

36 minutes ago, zoothorn said:

If I move controller to kitchen, trouble is it'll rarely get up above 19*, meaning it'll just be on almost continually.

That is the idea, should start to get the rest of the house warmer.

And make sure the thermostat is not above the oven.

 

As your system seems to have warmed the place up a bit, all be it slowly, it seems that most of it is working alright.  Don't get hung up on the absolute numbers on the thermostat, it is a warm house you are after.

 

 

[zoothorn]

5 minutes ago, SteamyTea said:

That is the idea, should start to get the rest of the house warmer.

And make sure the thermostat is not above the oven.

 

As your system seems to have warmed the place up a bit, all be it slowly, it seems that most of it is working alright.  Don't get hung up on the absolute numbers on the thermostat, it is a warm house you are after.

 

 

 

Hi ST. I understood the reason for suggesting putting it in kitchen, far more convenient, but the cost of running it.. is kinda primary factor, before me getting warm.

 

No the numbers- get that. I wonder what can be got from the '25* test' after all? afaict, it made no difference if I set it to 20.5* or 25*. It reached 20.5* in the same time, 3 hours. In fact rads might well have been -less- hot tonight. So that screws my nut in.

[ProDave]

If it's 5 degrees outside and you can't get the house more than 19 degrees, then you are going to struggle when winter gets here and it's sub zero outside.

 

I think we did ask earlier what heat loss calculations they did before fitting this system.  It is beginning to sound like they got those very wrong and the system is too small for your house?

 

As to running costs, the cost of running an ASHP is quite similar, perhaps marginally more than mains gas, so if you had say had a gas boiler instead, it might heat up quicker as the gas boiler would be more powerful, but the running costs would be about the same.

[ProDave]

2 minutes ago, zoothorn said:

I wonder what can be got from the '25* test' after all? afaict, it made no difference if I set it to 20.5* or 25*. It reached 20.5* in the same time, 3 hours. In fact rads might well have been -less- hot tonight. So that screws my nut in.

See my previous post, I think it shows that running flat out the system is barely able to cope with 5 degrees outside so will be under powered when you reach winter.

[SteamyTea]

2 minutes ago, zoothorn said:

I wonder what can be got from the '25* test' after all? afaict, it made no difference if I set it to 20.5* or 25*. It reached 20.5* in the same time, 3 hours

Does sound as though it is possibly undersized.  Or the heating curve is no steep enough i.e. it is only putting in 50% the power it can, when it should be putting in say 90%.

It is also possible to be a combination of both i.e a small engined car, stuck in 4th gear, going up a steep hill.  It will make it, but it will be slower

[zoothorn]

2 minutes ago, ProDave said:

If it's 5 degrees outside and you can't get the house more than 19 degrees, then you are going to struggle when winter gets here and it's sub zero outside.

 

I think we did ask earlier what heat loss calculations they did before fitting this system.  It is beginning to sound like they got those very wrong and the system is too small for your house?

 

As to running costs, the cost of running an ASHP is quite similar, perhaps marginally more than mains gas, so if you had say had a gas boiler instead, it might heat up quicker as the gas boiler would be more powerful, but the running costs would be about the same.

 

I know exactly. I did take a risk knowing that it might well struggle here, but did expect a bit more heat from the rads tbh. They just don't seem quite hot enough to be effective. Now this might change if it get colder & the outside thermometer adjust them up.. but I'm not holding my breath.

 

Glad to know its not more costly than another typical CH system tho.

 

thanks- zoot.

[zoothorn]

7 minutes ago, ProDave said:

See my previous post, I think it shows that running flat out the system is barely able to cope with 5 degrees outside so will be under powered when you reach winter.

 

Right, so the 'power' factor you mention here, is presumably determined by the no.of rads its running, if a bigger house is only determined to be so, from the pov of the system, by having more rads.

 

So, if I then turned off 2 rads, Ive effectively got instead of a 3 bed house as it is, a 2 bed house. And therefore, it should what run the 6x rads up to a higher temp?

[PeterW]

I think the thermostat needs moving and you need to probably bite the bullet for a week or two and get the system running up to 21-22c from 7am-9pm and start to get the fabric of the building up to temperature. Without that, you are going to struggle to get any warmth into the house. 

[zoothorn]

14 minutes ago, SteamyTea said:

Does sound as though it is possibly undersized.  Or the heating curve is no steep enough i.e. it is only putting in 50% the power it can, when it should be putting in say 90%.

It is also possible to be a combination of both i.e a small engined car, stuck in 4th gear, going up a steep hill.  It will make it, but it will be slower

 

I originally had a 5kW planned. But they changed to 7.5 just prior to fitting, actually to be on the safe side ~more or less the reasoning/ as cost was no issue to them. So I doubt the reason its perhaps not functioning effectively as it could, is that its undersized.

 

I just think the outside thermometer & whatever it influences is up the creek. I'll get me coat.