Where do I start?? CH system & DHW...
- Thread starter PeedOftec
- Start date
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It's not a pretty sight tbh.
There are plenty of "not so pretty sights" with this installation I'm afraid... and for a job thats costing me £13k plus I would have expected a decent job.....
Thankfully it's a "balance on completion", which at the moment, 6 months down the line, it isn't!.
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Just to keep you posted on what happened after the plumbers visit yesterday
He came and re-opened the heat leak rads valves and repositioned the high and low pipe thermostats. I have left them as they were for now.
When I got home the hot water tank was at about 65 degrees and the stove was “ticking over” nicely. Bearing in mind the stove had been on since 11:00 in the morning, plus the tank would have been warm from the immersion being on overnight. The CH pump was off (and hence the room radiators were off) and the heat leak rads were bouncing hot.
I purposely kept the stove ticking over, and re-fuelled mid evening. The stove boiled up at one point and I reduced the High pipe stat by about 5 degrees to kick in the CH pump.
The pump ran for a minute or so, barely heating the radiators, (although room heat wasn’t required) but the reverse flow through the coil in the tank will have stopped any more heat from the stove getting to the water in the tank. The cold water in the return radiator pipes would be passing through the coil effectively robbing heat from the tank somewhat as the "injector tee" doesn't seem to inject!!
The washing up was done and a bath run… after a period of about 30 mins another bath was run but the water was luke warm, bearable for a bath but no great volume and no cold water was required to top it up. This was around 10:30 - 11:00 last night. The stove was just below the “boiling point” and the heat leak rads were still bouncing hot. The room rads were cold.
I put more fuel on the stove before going to bed, leaving it ticking over.
This morning there was warm water, not hot water, warm water. We didn’t need to add any cold to get a wash. The flow pipe to the heat leak rads was as warm as the water and the return from the heat leak rad was cold. (all the stored heat was going up into the lofts heat leak rads!!)
The washing machine has been on this morning and I suspect there will be zero hot water this evening when we all get in from work/school etc
I am going to light the stove when I get home from work tonight to see if we can get a reasonable amount of hot water for a bath in a reasonable amount of time.
I have several concerns with the system as it stands which need addressing, SOME of these are:-
1) Lack of temperature of hot water in the tank yet the 20kw stove is capable of boiling the water.
2) Lack of volume of hot water for baths showers etc, there are at times 6 occupants in the property.
3) Lack of recovery time as we can only have one “decent” bath during the evening.
4) Wasteful of heat to the heat leak rads, the loft space must have been like a sauna last night!
I will keep you posted on what happens tonight.
.
.
.
Just to keep you posted on what happened after the plumbers visit yesterday
He came and re-opened the heat leak rads valves and repositioned the high and low pipe thermostats. I have left them as they were for now.
When I got home the hot water tank was at about 65 degrees and the stove was “ticking over” nicely. Bearing in mind the stove had been on since 11:00 in the morning, plus the tank would have been warm from the immersion being on overnight. The CH pump was off (and hence the room radiators were off) and the heat leak rads were bouncing hot.
I purposely kept the stove ticking over, and re-fuelled mid evening. The stove boiled up at one point and I reduced the High pipe stat by about 5 degrees to kick in the CH pump.
The pump ran for a minute or so, barely heating the radiators, (although room heat wasn’t required) but the reverse flow through the coil in the tank will have stopped any more heat from the stove getting to the water in the tank. The cold water in the return radiator pipes would be passing through the coil effectively robbing heat from the tank somewhat as the "injector tee" doesn't seem to inject!!
The washing up was done and a bath run… after a period of about 30 mins another bath was run but the water was luke warm, bearable for a bath but no great volume and no cold water was required to top it up. This was around 10:30 - 11:00 last night. The stove was just below the “boiling point” and the heat leak rads were still bouncing hot. The room rads were cold.
I put more fuel on the stove before going to bed, leaving it ticking over.
This morning there was warm water, not hot water, warm water. We didn’t need to add any cold to get a wash. The flow pipe to the heat leak rads was as warm as the water and the return from the heat leak rad was cold. (all the stored heat was going up into the lofts heat leak rads!!)
The washing machine has been on this morning and I suspect there will be zero hot water this evening when we all get in from work/school etc
I am going to light the stove when I get home from work tonight to see if we can get a reasonable amount of hot water for a bath in a reasonable amount of time.
I have several concerns with the system as it stands which need addressing, SOME of these are:-
1) Lack of temperature of hot water in the tank yet the 20kw stove is capable of boiling the water.
2) Lack of volume of hot water for baths showers etc, there are at times 6 occupants in the property.
3) Lack of recovery time as we can only have one “decent” bath during the evening.
4) Wasteful of heat to the heat leak rads, the loft space must have been like a sauna last night!
I will keep you posted on what happens tonight.
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Ok, HETAS registered guys, a question.....(or anybody with more knowledge than me!!) the heat leak rad "upstairs" piped up to a wood burning stove. Feed pipe up to rad branches off to the vent and the return back "downstairs".
This is to cater for a power outage in case the CH pump cannot send the excess heat around the room rads? correct?
Right, can I, within the regs, fit a valve on the return from the heat leak rad to close it off when the power is ok, and open the valve if the power trips?
Reason - at the moment when I light the woodstove the heat leak rad is bouncing hot, robbing heat from the DHW tank.. what a waste!! (and in my case the heat leak rad is in the loftspace as it's a bungalow.
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Ok, HETAS registered guys, a question.....(or anybody with more knowledge than me!!) the heat leak rad "upstairs" piped up to a wood burning stove. Feed pipe up to rad branches off to the vent and the return back "downstairs".
This is to cater for a power outage in case the CH pump cannot send the excess heat around the room rads? correct?
Right, can I, within the regs, fit a valve on the return from the heat leak rad to close it off when the power is ok, and open the valve if the power trips?
Reason - at the moment when I light the woodstove the heat leak rad is bouncing hot, robbing heat from the DHW tank.. what a waste!! (and in my case the heat leak rad is in the loftspace as it's a bungalow.
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The stove is a Woodwarm Fireview 20kw fully boilered with split saddle and roof boilers.
Yes, it has it's own circulation pump for the rads that kicks in with the pipe stats. located near the DHW tank
http://www.metaldevelopments.co.uk/woodwarm/
Sorry, I was refering to the pipe stats when I said near the tank. The rads pump for the stove is just under the floorboards on the return to the stove, about 6 feet before the so called "injector tee" in the piccy. (will post a piccy of the pump in a mo.)
Yes, the pump in the piccy is the oil one that has the two valves just after it for water and rads circuits.
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Ok, piccy of rads pump for woodstove looking down onto floor. (should have rotated piccy really.)
Pipe in order left to right:-
1 - Oil return flowing up piccy
2 - Stove return with pump (hidden by floorjoist) flow up piccy
3 - Stove flow from stove after tee'ing off from gravity circ, flow down piccy to rads
4 - Oil flow to rads. flow down piccy
1 & 2 tee into each other bottom left of piccy
3 & 4 tee into each other bottom right of piccy.
Note non return valves cos of reverse flow.
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Ok, piccy of rads pump for woodstove looking down onto floor. (should have rotated piccy really.)
Pipe in order left to right:-
1 - Oil return flowing up piccy
2 - Stove return with pump (hidden by floorjoist) flow up piccy
3 - Stove flow from stove after tee'ing off from gravity circ, flow down piccy to rads
4 - Oil flow to rads. flow down piccy
1 & 2 tee into each other bottom left of piccy
3 & 4 tee into each other bottom right of piccy.
Note non return valves cos of reverse flow.
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Stove has been going for 2 1/2 hours, the tank is warm, not hot. It will be a lottery who gets the ONE luke warm bath tonight!!
The heat leak rad return pipe is too hot to touch and I have used 3 buckets of coal!! The room rads haven't been on either.
Just been in the loft, the heat leak rads are screaming hot!! What a bloody waste of heat!
Goes back to my question of "Can I turn them off if the power is ok?" The system would still be vented even if they were turned off.
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Stove has been going for 2 1/2 hours, the tank is warm, not hot. It will be a lottery who gets the ONE luke warm bath tonight!!
The heat leak rad return pipe is too hot to touch and I have used 3 buckets of coal!! The room rads haven't been on either.
Just been in the loft, the heat leak rads are screaming hot!! What a bloody waste of heat!
Goes back to my question of "Can I turn them off if the power is ok?" The system would still be vented even if they were turned off.
You can try turning the heat leak rad/rads off.
Bearing in mind the system is not plumbed as recommended by ACV then you need to be careful.
The coil along with the pipework may create too much resistance for gravity flow thus giving way for stove pump too operate.
The heat leak rad is sited much higher in your system so its thermosyphoning influence will be greater.
I think if the stove pump was operated by a store stat then the stove may over heat. The solution to this is an accelerator circuit or pipe the stove to the store as recommended.
You shouldn't need an injector T with your set up as it is because the store should already be up to temperature when the stove pump operates.
The tappings in any case to the heat leak rad should be sited lower than the set of tapping into the store to prevent gravity circulation between the gravity circulation between the heat leak and the store which sounds as though is happening with your system.
Connected and sized correctly the thermal store will obviate the need for heat leak rads.
Bearing in mind the system is not plumbed as recommended by ACV then you need to be careful.
The coil along with the pipework may create too much resistance for gravity flow thus giving way for stove pump too operate.
The heat leak rad is sited much higher in your system so its thermosyphoning influence will be greater.
I think if the stove pump was operated by a store stat then the stove may over heat. The solution to this is an accelerator circuit or pipe the stove to the store as recommended.
You shouldn't need an injector T with your set up as it is because the store should already be up to temperature when the stove pump operates.
The tappings in any case to the heat leak rad should be sited lower than the set of tapping into the store to prevent gravity circulation between the gravity circulation between the heat leak and the store which sounds as though is happening with your system.
Connected and sized correctly the thermal store will obviate the need for heat leak rads.
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Yes, the ACV guys told me the coil is 10x the resistance of the correct tappings. Told the plumber and he said "what do you mean?"!!
Yes again, when the stove is out the heat leak rads actually draw heat OUT of the tank via thermosyphoning cos the rad is higher than the tank.
Question, the pipe stats could be placed virtually at the stove set at 95 degrees or at the DHW tank set at say 75 degrees, both would kick the CH pump on when the heat IN the stove was at 100. All theoretical approximate figures, more looking at the theory behind it. (if that makes sense) What in your opinion would be the best place for the stats, back of the stove or connections on tank?
Don't the regs stipulate that a heat leak rad is required?
Lastly, you mention turning off the heat leak, brings me back to my post as few back, can I put a gate valve or whatever in the RETURN from the heat leak rad? (note the vent tees off from the feed to the heat leak rad)
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PS what part of the world are you Mr. Norcon?
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Yes, the ACV guys told me the coil is 10x the resistance of the correct tappings. Told the plumber and he said "what do you mean?"!!
Yes again, when the stove is out the heat leak rads actually draw heat OUT of the tank via thermosyphoning cos the rad is higher than the tank.
Question, the pipe stats could be placed virtually at the stove set at 95 degrees or at the DHW tank set at say 75 degrees, both would kick the CH pump on when the heat IN the stove was at 100. All theoretical approximate figures, more looking at the theory behind it. (if that makes sense) What in your opinion would be the best place for the stats, back of the stove or connections on tank?
Don't the regs stipulate that a heat leak rad is required?
Lastly, you mention turning off the heat leak, brings me back to my post as few back, can I put a gate valve or whatever in the RETURN from the heat leak rad? (note the vent tees off from the feed to the heat leak rad)
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PS what part of the world are you Mr. Norcon?
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If the tank was up to temp, without an injector tee the cold water in the return from the rads would (actually is!) "reverse flowing" through the coil when the pump kicks in and draws heat AWAY from the tank and round the rads.
If you trhink about it like an electric circuit the tank and the stove are connnected in parallel after the pump and the flow needs to be cajoled to go the correct way via injector tee or other means.
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Yes you are right. The injector T would be a big help to prevent reverse circulation.
Page 17 in the link below shows a schematic which is (I think) what you have installed albeit using an SLME 300.
http://www.waterfordstanley.com/SiteImages/Site_131/PDF/BrandonOilInstMK3.pdf
You should refer to the manufacturers instructions but most afaik are fitted close to the stove.
Some use hi-lo stat configurations whilst some have only one stat energising the pump.
Some like the Stanley above don't show the injector T whilst others like Rayburn insist on the injector T.
As in all cases....
The system must be installed in accordance with local water bylaws, Building Regulations and British standards and it is strongly encouraged that the plumbing be carried out by a competent person.
Page 17 in the link below shows a schematic which is (I think) what you have installed albeit using an SLME 300.
http://www.waterfordstanley.com/SiteImages/Site_131/PDF/BrandonOilInstMK3.pdf
You should refer to the manufacturers instructions but most afaik are fitted close to the stove.
Some use hi-lo stat configurations whilst some have only one stat energising the pump.
Some like the Stanley above don't show the injector T whilst others like Rayburn insist on the injector T.
As in all cases....
The system must be installed in accordance with local water bylaws, Building Regulations and British standards and it is strongly encouraged that the plumbing be carried out by a competent person.
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Well have been on phone to plumber again tonight and he tentatively admits the system is wrong and is suggesting taking the ACV tank out.
I think it is as a result of me emailing back to his office and letting the office know what is going on every time he visits.
Now talking about a "saddle tank" and putting it up in the loft space. Whats a saddle tank?
At least it means we get the kitchen space back where the thermal store is if it all goes ahead.
SO.... now is the final chance to get a system that works..... come on all you experts... what questions should I be asking of the plumber and what should I be telling him I need??
I don't want to rely on one energy source, the wood stove, oil boiler and immersion heater all need to work together and/or independantly. I also need the provision to add solar in the near future.
Cheers guys,
S.
.
.
.
Well have been on phone to plumber again tonight and he tentatively admits the system is wrong and is suggesting taking the ACV tank out.
I think it is as a result of me emailing back to his office and letting the office know what is going on every time he visits.
Now talking about a "saddle tank" and putting it up in the loft space. Whats a saddle tank?
At least it means we get the kitchen space back where the thermal store is if it all goes ahead.
SO.... now is the final chance to get a system that works..... come on all you experts... what questions should I be asking of the plumber and what should I be telling him I need??
I don't want to rely on one energy source, the wood stove, oil boiler and immersion heater all need to work together and/or independantly. I also need the provision to add solar in the near future.
Cheers guys,
S.
.
.
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