Hello all,
Sorry in advance for the long post, but I hope a lot of detail will help you help me! I'd appreciate some assistance from you experienced guys with a persistent problem relating to a heating system I've been working on for a customer.
I recently fitted a indirect cylinder for a customer after their original one split, a relatively easy job however there seem to have been a number of issues with the heating system since I installed it.
I'll give you a little background information. Their system comprises of:
- Potterton Suprima 100
- Vented direct cylinder, controlled by a two port valve.
- 2 Heating zones, upstairs and downstairs, each controlled by a two port valve.
- 2 Room stats, one for each heating zone.
- 1 FP715 programmer controlling upstairs heating and DHW.
- 1 TS715-si controlling downstairs heating.
- 1 Frost Stat
- 1 Grundfos pump.
- The central heating system is sealed.
Issues started soon after the installation, upon refilling the system after replacing the cylinder and firing the system I noticed that the boiler kept locking out, not on a regular basis but maybe 2-3 times a day, with the red light on the boiler flashing 5 times in 10 seconds, this could be reset after about 10 minutes so obviously it's an overheat fault.
During the initial few days of it failing I took air out of the system on a number of occasions and topped up accordingly, however the fault continued. At the same time the heat exchanger of the boiler developed a leak and had to be exchanged. I'm not Gas Safe so this was carried out by another engineer.
The boiler is 18 years old and the engineer explained to the owner that it was probably due to wear and tear. The original overheat fault continued. At this point the homeowner called the Gas Safe engineer in and he checked the two thermostats and swapped the PCB with a spare he had that worked, however the problem of it locking out persists.
On top of all this the frost stat shorted and kept tripping the heating's electrical circuit, easy to diagnose and replace so this is now working.
As the system was working without issue before I replaced the cylinder I feel obliged (quite rightly) to sort the issue, the problem is I'm stuck now. I've electrically tested the pump, valves, cylinder stat and room stats but the boiler still locks out on a irregular basis, still 2-3 times a day.
The homeowner has gone on holiday for a couple of weeks so it's given me a chance to work on it and get it sorted.
The only other thing to mention is that I had the system working on 'AUTO' for a couple of days with the room stats turned to about 12 degrees, as soon as this was turned to 'ALL DAY' with the stat turned up the boiler locked out again, not sure how long it fired for as I went away from the property.
I have also noticed that the boiler only ever fires for about 2 minutes at a time and there seems to be a kettling or boiling sound when it is fired. Could it be a blockage?
Many thanks to you all in advance, if you need further information please let me know.
Mark
Sorry in advance for the long post, but I hope a lot of detail will help you help me! I'd appreciate some assistance from you experienced guys with a persistent problem relating to a heating system I've been working on for a customer.
I recently fitted a indirect cylinder for a customer after their original one split, a relatively easy job however there seem to have been a number of issues with the heating system since I installed it.
I'll give you a little background information. Their system comprises of:
- Potterton Suprima 100
- Vented direct cylinder, controlled by a two port valve.
- 2 Heating zones, upstairs and downstairs, each controlled by a two port valve.
- 2 Room stats, one for each heating zone.
- 1 FP715 programmer controlling upstairs heating and DHW.
- 1 TS715-si controlling downstairs heating.
- 1 Frost Stat
- 1 Grundfos pump.
- The central heating system is sealed.
Issues started soon after the installation, upon refilling the system after replacing the cylinder and firing the system I noticed that the boiler kept locking out, not on a regular basis but maybe 2-3 times a day, with the red light on the boiler flashing 5 times in 10 seconds, this could be reset after about 10 minutes so obviously it's an overheat fault.
During the initial few days of it failing I took air out of the system on a number of occasions and topped up accordingly, however the fault continued. At the same time the heat exchanger of the boiler developed a leak and had to be exchanged. I'm not Gas Safe so this was carried out by another engineer.
The boiler is 18 years old and the engineer explained to the owner that it was probably due to wear and tear. The original overheat fault continued. At this point the homeowner called the Gas Safe engineer in and he checked the two thermostats and swapped the PCB with a spare he had that worked, however the problem of it locking out persists.
On top of all this the frost stat shorted and kept tripping the heating's electrical circuit, easy to diagnose and replace so this is now working.
As the system was working without issue before I replaced the cylinder I feel obliged (quite rightly) to sort the issue, the problem is I'm stuck now. I've electrically tested the pump, valves, cylinder stat and room stats but the boiler still locks out on a irregular basis, still 2-3 times a day.
The homeowner has gone on holiday for a couple of weeks so it's given me a chance to work on it and get it sorted.
The only other thing to mention is that I had the system working on 'AUTO' for a couple of days with the room stats turned to about 12 degrees, as soon as this was turned to 'ALL DAY' with the stat turned up the boiler locked out again, not sure how long it fired for as I went away from the property.
I have also noticed that the boiler only ever fires for about 2 minutes at a time and there seems to be a kettling or boiling sound when it is fired. Could it be a blockage?
Many thanks to you all in advance, if you need further information please let me know.
Mark