R
Roblion
Hello all,
Firstly you know it's serious when a guy has to ask for help!
My first time here....
My System is;
Potterton Netaheat Profile 80e (about 15-20 years old) Boiler thermosat set to 3 normally
fully pump fed with grundfos pump set on speed 2
Honeywell Smartfit control panel and programmer (S plan). Temp Water set to 60oC, CH set to 22oC
2 x honeywell smartfit zone valves (#1 is Hot Water, #2 is CH) both 2 port. The leaver has 3 positions, A = Closed, Fill/Vent = Open, B = ???
OK list of problems......
The system had been working no problem all summer for timed HW and occasional CH. On start of cold weather, the system stopped and would not re light. Boiler thermal cut out was NOT out. Engineer called - replaced Fan, control thermostat and pump overrun thermometer, now boiler starts up first time..
However, the boiler thermal cut out pops if set above 1, (normally set at 3). Set at 1 the system can not meet the CH and HW temps demands.
Set at 2 we get some kettling, and thermal cut out pops out.
Set at 3 we get severe kettling, even venting to CH fill tank.
Set above 3 it sounds like NASA has just launched a spaceshuttle from our kitchen!
It all seems to happen when after the desired temps are met, the boiler shuts off normally, and both values open to dissipate heat, the pump is running, but after a few seconds to minutes the thermal cut out pops.... However, it also seem that the system SOMETIMES ignores what temps are set and continues to heat CH or HW beyond what is asked......
Pump replaced with new one..... old one has some black dirt in it. Still no change to problem.
Fill tank is clean, water-in valve works ok.
If pump is set to speed 3.... the system continuously vents hot water back to the fill tank.
Most pipework is 22mm except the bypass balancing valve pipe which is 15mm. There is no bypass radiator. Radiators around house are microbore.
Now the Engineer is saying we need to powerfush the system to clean it out..... but it will cost!! and he is unsure if it will fix problem or that we may cause a blow in the pipework somewhere.
Help........ Please guys....what should i do????
Thanks in advance..
Rob
Firstly you know it's serious when a guy has to ask for help!
My first time here....
My System is;
Potterton Netaheat Profile 80e (about 15-20 years old) Boiler thermosat set to 3 normally
fully pump fed with grundfos pump set on speed 2
Honeywell Smartfit control panel and programmer (S plan). Temp Water set to 60oC, CH set to 22oC
2 x honeywell smartfit zone valves (#1 is Hot Water, #2 is CH) both 2 port. The leaver has 3 positions, A = Closed, Fill/Vent = Open, B = ???
OK list of problems......
The system had been working no problem all summer for timed HW and occasional CH. On start of cold weather, the system stopped and would not re light. Boiler thermal cut out was NOT out. Engineer called - replaced Fan, control thermostat and pump overrun thermometer, now boiler starts up first time..
However, the boiler thermal cut out pops if set above 1, (normally set at 3). Set at 1 the system can not meet the CH and HW temps demands.
Set at 2 we get some kettling, and thermal cut out pops out.
Set at 3 we get severe kettling, even venting to CH fill tank.
Set above 3 it sounds like NASA has just launched a spaceshuttle from our kitchen!
It all seems to happen when after the desired temps are met, the boiler shuts off normally, and both values open to dissipate heat, the pump is running, but after a few seconds to minutes the thermal cut out pops.... However, it also seem that the system SOMETIMES ignores what temps are set and continues to heat CH or HW beyond what is asked......
Pump replaced with new one..... old one has some black dirt in it. Still no change to problem.
Fill tank is clean, water-in valve works ok.
If pump is set to speed 3.... the system continuously vents hot water back to the fill tank.
Most pipework is 22mm except the bypass balancing valve pipe which is 15mm. There is no bypass radiator. Radiators around house are microbore.
Now the Engineer is saying we need to powerfush the system to clean it out..... but it will cost!! and he is unsure if it will fix problem or that we may cause a blow in the pipework somewhere.
Help........ Please guys....what should i do????
Thanks in advance..
Rob
