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Post by rocketmanbkk on Feb 25, 2021 15:15:30 GMT
Hello
I’ve got a 180 litre unvented next to the24kw boiler.
From cold water it takes 51 minutes to heat to 60°. Yes, I sat in the loft & timed when the boiler shut off!!!
Coming from a combi boiler to this is trial & error still.
I put the water on at 0530hrs for an hour.
I shower etc. Her indoors showers & washes up.
Today Rct Jnr went in the shower & it went cold.
I turned the water on again and 51 minutes the boiler cut out, yes I went in the loft again to tome
time it. The water is red hot again.
What sort of usage should I get from 180 litres?
I though we’d all get showered, washed up twice a day & her indoors showered again in the evening but it doesn’t seem to be that way so I’ll need to put the water on again for half an hour @1700hrs.
Anyone with experience of these systems?
Maybe my expectations were too high
Cheers all
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Post by DIYDafty on Feb 25, 2021 15:52:54 GMT
Right I just checked and my cylinder is a gledhill 1500x450 which I think makes it 218 Litres so not as big as I thought. I've never timed it but would guess about 30 minutes.
Its enough water for 2 "normal" good power showers plus daytime usage or 1 absolutely ridiculously massive shower marathon my wife sometimes has. I normally put the HW on most of the day obvisouly with the stat regulating it and don't get down to cold.
You're lucky though that your boiler doesn't cycle as mine does. I don't like running the pump on top speed 3 - maybe I should? Dunno what else I can do - the boiler stat is on 4 out of 6. Any ideas ?
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Post by rocketmanbkk on Feb 25, 2021 16:05:39 GMT
So that begs the question about whether a it’s more economical to leave the water on & let the thermostat turn it on & off.
Mmmmmm...
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Post by tomplum on Feb 25, 2021 16:07:48 GMT
I would have expected better than that too so, how much washing up was done and how long are you showering for, I did an experiment in plumber towers one year, I had what I would call a normal shower and ran the waste in a bucket to measure it, Although I thought it was a quick shower, the bucket was full, So I am using aprox 5 gallons/21 litres for a quick shower, So going off that, you used 21 litres, Mrs rocket used the same and lets guess at 30 lites to wash up giving 72 lites,
now a 180 litre cylinder should hold 120 litres of hot water then some more at a less temp with cold water at the bottom,
So your well short of what you should be getting and its taking longer to recover, I'd expect a full cylinder in 20 mins to half an hour,
start by checking the output of the boiler, This will need a gas rating exercise, put the boiler on full setting and measure how much gas its using, then the pipework to the cylinder, this needs to be in 22mm to the cylinder,
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Post by tomplum on Feb 25, 2021 16:11:57 GMT
gas rating
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Post by rocketmanbkk on Feb 25, 2021 16:14:03 GMT
I would have expected better than that too so, how much washing up was done and how long are you showering for, I did an experiment in plumber towers one year, I had what I would call a normal shower and ran the waste in a bucket to measure it, Although I thought it was a quick shower, the bucket was full, So I am using aprox 5 gallons/21 litres for a quick shower, So going off that, you used 21 litres, Mrs rocket used the same and lets guess at 30 lites to wash up giving 72 lites, now a 180 litre cylinder should hold 120 litres of hot water then some more at a less temp with cold water at the bottom, So your well short of what you should be getting and its taking longer to recover, I'd expect a full cylinder in 20 mins to half an hour, start by checking the output of the boiler, This will need a gas rating exercise, put the boiler on full setting and measure how much gas its using, then the pipework to the cylinder, this needs to be in 22mm to the cylinder, Yeah. Everything is in 22mm & the boiler is a foot away so no long runs. Mmmmmm.... boiler seems good but I’ll get my mate to test the gas rate. Cheers |
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Post by DIYDafty on Feb 25, 2021 16:45:59 GMT
I've got a very long run from the boiler in the garage to the cylinder in the airingcupboard although it is done in 28mm.
Why does the boiler cycle on and off and should I care much if its been doing it for 20 years ?
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Post by battle1066 on Feb 25, 2021 17:58:00 GMT
I've got a very long run from the boiler in the garage to the cylinder in the airingcupboard although it is done in 28mm. Why does the boiler cycle on and off and should I care much if its been doing it for 20 years ? Is the cycling after its reached the tanks stat requirements or are you saying the boiler is cycling between the time it takes for the cylinder stat requirements? |
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Post by crowsfoot on Feb 25, 2021 18:01:26 GMT
It surely must be an old gravity system with 28mm circ's dd?
So circulation will be slow and steady.
The boilers reaching temperature on it's own boiler stat and switching itself off until the slow movement of colder returning water to the boiler takes the temperature low enough for the boiler to fire up again. It's normal for this type of system.
Rocky, Mains fed high pressure Hot water supplied at the taps from an unvented cylinder can empty a stored water unvented really fast and as it's emptied it's cooling itself down quickly with mains cold water.
I'd personally leave the hot water on an all day setting if I was you - hot water recovery rate will be a lot faster on your system than on dds!
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Post by rocketmanbkk on Feb 25, 2021 18:16:31 GMT
It surely must be an old gravity system with 28mm circ's dd? So circulation will be slow and steady. The boilers reaching temperature on it's own boiler stat and switching itself off until the slow movement of colder returning water to the boiler takes the temperature low enough for the boiler to fire up again. It's normal for this type of system. Rocky, Mains fed high pressure Hot water supplied at the taps from an unvented cylinder can empty a stored water unvented really fast and as it's emptied it's cooling itself down quickly with mains cold water. I'd personally leave the hot water on an all day setting if I was you - hot water recovery rate will be a lot faster on your system than on dds! Ok cheers. |
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Post by DIYDafty on Feb 25, 2021 18:34:19 GMT
I've got a very long run from the boiler in the garage to the cylinder in the airingcupboard although it is done in 28mm. Why does the boiler cycle on and off and should I care much if its been doing it for 20 years ? Is the cycling after its reached the tanks stat requirements or are you saying the boiler is cycling between the time it takes for the cylinder stat requirements? Cycling as it heats up and for the heating too. Even when its heating cyliunder from cold and all of the rads from cold it still cycles but I think less frequently. Tappy says its normal for my kind of system so sounds like no bother? I don't think those pipes were part of gravity as they rise up to the ceiling above garage, then horizontally across one big room above the garage, a second bedroom and finally into airing cupboard. I would have thought it would be optimal for the boiler to run constantly when the stats are demanding heat (especially both of them). Any tips on adjusting boiler water temperature ? As I say I really don't want to run pump on top unless I really have too coz its noisy. Rocky: SOrry for hijacking your thread - tell me to bugger off and create a new one if you want |
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Post by crowsfoot on Feb 25, 2021 19:09:00 GMT
The boiler thermostat is the #1 stat in charge of the boiler.
Is this in the Ukraine property dd?
If it is gravity circ's then you shouldn't have to run that noisy pump for the hot water to work.
I would've thought the lower temperature the boiler stat is set at then the less boiler cycling will take place.
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Post by battle1066 on Feb 25, 2021 19:09:08 GMT
Is the cycling after its reached the tanks stat requirements or are you saying the boiler is cycling between the time it takes for the cylinder stat requirements? Cycling as it heats up and for the heating too. Even when its heating cyliunder from cold and all of the rads from cold it still cycles but I think less frequently. Tappy says its normal for my kind of system so sounds like no bother? I don't think those pipes were part of gravity as they rise up to the ceiling above garage, then horizontally across one big room above the garage, a second bedroom and finally into airing cupboard. I would have thought it would be optimal for the boiler to run constantly when the stats are demanding heat (especially both of them). Any tips on adjusting boiler water temperature ? As I say I really don't want to run pump on top unless I really have too coz its noisy. Rocky: SOrry for hijacking your thread - tell me to bugger off and create a new one if you want It would be worth doing the magnet test first at various points within your system first to see if you have a magnatite restriction on a bend or return to the expansion tank. if that checks out ok then its buying couple of pipe thermometers to test the boiler stat. |
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Post by dickpuller on Feb 25, 2021 21:24:43 GMT
Hello I’ve got a 180 litre unvented next to the24kw boiler. From cold water it takes 51 minutes to heat to 60°. Yes, I sat in the loft & timed when the boiler shut off!!! Coming from a combi boiler to this is trial & error still. I put the water on at 0530hrs for an hour. I shower etc. Her indoors showers & washes up. Today Rct Jnr went in the shower & it went cold. I turned the water on again and 51 minutes the boiler cut out, yes I went in the loft again to tome time it. The water is red hot again. What sort of usage should I get from 180 litres? I though we’d all get showered, washed up twice a day & her indoors showered again in the evening but it doesn’t seem to be that way so I’ll need to put the water on again for half an hour @1700hrs. Anyone with experience of these systems? Maybe my expectations were too high Cheers all So you’re saying you have a Combi boiler heating an unvented cylinder? If that’s the case you could Plate Heat the cylinder, this would give you a far better HW recovery rate. If it’s a 24KW Combi, the output to CH(& cylinder) will be limited. I’d like confirmation of the way it’s piped up & wiring, before I can confirm your set-up mate👍 |
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Post by rocketmanbkk on Feb 26, 2021 13:03:25 GMT
Hello I’ve got a 180 litre unvented next to the24kw boiler. From cold water it takes 51 minutes to heat to 60°. Yes, I sat in the loft & timed when the boiler shut off!!! Coming from a combi boiler to this is trial & error still. I put the water on at 0530hrs for an hour. I shower etc. Her indoors showers & washes up. Today Rct Jnr went in the shower & it went cold. I turned the water on again and 51 minutes the boiler cut out, yes I went in the loft again to tome time it. The water is red hot again. What sort of usage should I get from 180 litres? I though we’d all get showered, washed up twice a day & her indoors showered again in the evening but it doesn’t seem to be that way so I’ll need to put the water on again for half an hour @1700hrs. Anyone with experience of these systems? Maybe my expectations were too high Cheers all So you’re saying you have a Combi boiler heating an unvented cylinder? If that’s the case you could Plate Heat the cylinder, this would give you a far better HW recovery rate. If it’s a 24KW Combi, the output to CH(& cylinder) will be limited. I’d like confirmation of the way it’s piped up & wiring, before I can confirm your set-up mate👍 No it’s a heat only boiler, not a combi |
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