Hi all by way of introduction My name is Clive, I am CORGI regd but have been saddled with a bit of a mare job which is really for the HETAS boys is there any out there able to help.
I got a mate with a Hunter solid fuel burner in front room, got DHW cylinder and 2 pumps in airing cupboard on same level next door so approx 4metres away.
Twin flow and returns to the back of the burner which should rise all the way to the cylinder but immediately drop down to the floor and then run horizontal the DHW pump is pumping the wrong way and it is pumping over into the F&E because the vent is positive.
When we sparked up the fire it took 1 hour to raise system water by 20C so very little differential consequently could not tell at the back of the burner which tappings were acting as the flow and returns.
After about 3 or 4 hours I didn't witness it but all hell breaks loose and the whole thing overheats sounds like the burner is going to blow up vents a whole load of steam and hot water out of the F&E. This has been going on for 2 years so every day in winter for 2 years he has to bleed the rads, he has mentioned it before but it was more of a talking point than can you come round and have a look.
I found that there are no AAV's on the high points behind the burner to the flow and return pipework, I know if it was piped up correctly ie rising all the way the cylinder the vent would eventually take care of trapped air.
Also the cold feed and vent are in no way as they should be. Vent is on the flow after the pump so vent is positive and this makes me think the pump has been changed and put the wrong way round. The cold feed is on the return side of the cylinder but still positive.
The radiators never get hot just luke warm so if this is all sucking and blowing in the wrong directions could there be an anti grav valve somewhere stopping the reversed flow? I know that this is very long winded and a bit of a chore to read and understand its a lot easier looking at the thing so hopefully I have included some pictures below. I think I may have actually answered some of my own questions here but thought I would ask anyway.
Main difference that I noted is that there is a pipestat on the heating return which calls to the CH & DHW pumps to energise when water from the return reaches a pre set temp, kind of opposite to the way I am used to but I understand the need for this which is to get the heat away from the burner.
Pictures of the job
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1217.jpg
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1219.jpg
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1218.jpg
You can see the flow pipework on the top picture above it's the 22mm on the far right top one of the 4 horizontals. I think the flows should be 28? but that could be the least of the problems. I can't think how you would possibly stop there being a build up of air in the pipework? So I would think an AAV at the highest point inside the fireplace opening as minimum?
The pipe stat 2nd pipe down on the horizontals is fitted to the return pipework which is obviously wrong as it would take an age for the return pipework to heat up enough to energise the pumps. This in its self could be the problem causing the overheating and boiling of water in the burner i think?
DHW pump shown at low level pumping up into bottom of cylinder with vent teeing off just before bottom tapping. So vent must be positive, you can make out 15mm cold feed teed off on return top tapping. Pump has been installed wrong way round.
Going to reverse pump and relocate cold feed between vent and pump, if I go down and then back up is it alright to connect with a tee in the vertical pipework? all the pictures I have ever seen show connecting into horizontal pipework?
From left to right pipes against the wall at high level.
1. 22 Cold feed to DHW cylinder
2. 22 DHW pipework & Vent
3. 22 CH Vent
4. 15 Mains cold
5. 15 Cold feed to Heating system (will remove gate valve)
6. 22 CH return
7. 22 CH flow
8. 15mm pipe on the p*ss another cold distribution
9. 15 Connected to 4.
As I said it is a bit of a mishmash took a bit of time to get my head round, the pumps only come on to get the heat away from the boiler, all the time the fire is going the pumps stay on only stopping when heat from fire drops below 70 - 80C
Immersion heater connected to Economy 7 but cylinder stat not connected and in wrong place will recommend spark looks at that one.
Any help on this one very much appreciated.
Regards Clive
I originally emailed Hunters Tech and have had this reply.
Hello Clive,
I think your thoughts are correct, there is probably air in the pipe system. In order to get a decent gravity flow, to the hot water tank, the flow pipe must be rising, all the way to the Hot water Tank.
You are going to reverse "one"of the pumps? Does this mean the the hot water system is pumped? We would not recommend this. This part of the circuit should be a gravity flow.
I hope this helps.
So this gets me thinking a bit more. As I remember it shouldn't the size of cylinder for Solid fuel be 200L + ? It's all adding up to a bit of a nightmare.
Regards Clive[/img]
I got a mate with a Hunter solid fuel burner in front room, got DHW cylinder and 2 pumps in airing cupboard on same level next door so approx 4metres away.
Twin flow and returns to the back of the burner which should rise all the way to the cylinder but immediately drop down to the floor and then run horizontal the DHW pump is pumping the wrong way and it is pumping over into the F&E because the vent is positive.
When we sparked up the fire it took 1 hour to raise system water by 20C so very little differential consequently could not tell at the back of the burner which tappings were acting as the flow and returns.
After about 3 or 4 hours I didn't witness it but all hell breaks loose and the whole thing overheats sounds like the burner is going to blow up vents a whole load of steam and hot water out of the F&E. This has been going on for 2 years so every day in winter for 2 years he has to bleed the rads, he has mentioned it before but it was more of a talking point than can you come round and have a look.
I found that there are no AAV's on the high points behind the burner to the flow and return pipework, I know if it was piped up correctly ie rising all the way the cylinder the vent would eventually take care of trapped air.
Also the cold feed and vent are in no way as they should be. Vent is on the flow after the pump so vent is positive and this makes me think the pump has been changed and put the wrong way round. The cold feed is on the return side of the cylinder but still positive.
The radiators never get hot just luke warm so if this is all sucking and blowing in the wrong directions could there be an anti grav valve somewhere stopping the reversed flow? I know that this is very long winded and a bit of a chore to read and understand its a lot easier looking at the thing so hopefully I have included some pictures below. I think I may have actually answered some of my own questions here but thought I would ask anyway.
Main difference that I noted is that there is a pipestat on the heating return which calls to the CH & DHW pumps to energise when water from the return reaches a pre set temp, kind of opposite to the way I am used to but I understand the need for this which is to get the heat away from the burner.
Pictures of the job
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1217.jpg
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1219.jpg
http://i72.photobucket.com/albums/i193/IDIDDIDI/IMG_1218.jpg
You can see the flow pipework on the top picture above it's the 22mm on the far right top one of the 4 horizontals. I think the flows should be 28? but that could be the least of the problems. I can't think how you would possibly stop there being a build up of air in the pipework? So I would think an AAV at the highest point inside the fireplace opening as minimum?
The pipe stat 2nd pipe down on the horizontals is fitted to the return pipework which is obviously wrong as it would take an age for the return pipework to heat up enough to energise the pumps. This in its self could be the problem causing the overheating and boiling of water in the burner i think?
DHW pump shown at low level pumping up into bottom of cylinder with vent teeing off just before bottom tapping. So vent must be positive, you can make out 15mm cold feed teed off on return top tapping. Pump has been installed wrong way round.
Going to reverse pump and relocate cold feed between vent and pump, if I go down and then back up is it alright to connect with a tee in the vertical pipework? all the pictures I have ever seen show connecting into horizontal pipework?
From left to right pipes against the wall at high level.
1. 22 Cold feed to DHW cylinder
2. 22 DHW pipework & Vent
3. 22 CH Vent
4. 15 Mains cold
5. 15 Cold feed to Heating system (will remove gate valve)
6. 22 CH return
7. 22 CH flow
8. 15mm pipe on the p*ss another cold distribution
9. 15 Connected to 4.
As I said it is a bit of a mishmash took a bit of time to get my head round, the pumps only come on to get the heat away from the boiler, all the time the fire is going the pumps stay on only stopping when heat from fire drops below 70 - 80C
Immersion heater connected to Economy 7 but cylinder stat not connected and in wrong place will recommend spark looks at that one.
Any help on this one very much appreciated.
Regards Clive
I originally emailed Hunters Tech and have had this reply.
Hello Clive,
I think your thoughts are correct, there is probably air in the pipe system. In order to get a decent gravity flow, to the hot water tank, the flow pipe must be rising, all the way to the Hot water Tank.
You are going to reverse "one"of the pumps? Does this mean the the hot water system is pumped? We would not recommend this. This part of the circuit should be a gravity flow.
I hope this helps.
So this gets me thinking a bit more. As I remember it shouldn't the size of cylinder for Solid fuel be 200L + ? It's all adding up to a bit of a nightmare.
Regards Clive[/img]
