Hello everyone. Firstly, apologies for the length of this post, however my central heating saga has been ongoing for several months so there is lots of history.
I have a Potterton Suprima 40l Gas boiler, with a Santon Premier unvented hotwater tank. I have 12 rads, microbore piping, Grundfos 15-50 pump (running at speed 3) and a Lifestyle LP522 programmer. I bought my house new 4 years ago from Barratt.
There is a Drayton Roomstat (RTS 1 I think) in the Lounge and individual TRVs on all but 2 of the rads (1 upstairs, 1 downstairs)
There is also 1 Drayton ZA5 zone actuator (heating) and 1 Honeywell motorised valve (hot water)
The system was drained down in August last year to add some TRVs and thats when the problems began.
At the time of refilling no inhibitor was added to the system, although I didn't know about this until 2 months later when I called the plumber to ask why the heating wasn't working as well as it had been prior to the work. He casually mentioned at the time that he had meant to drop off a bottle of inhibitor for me to add to the system but he forgot!
The symptoms at that point were lukewarm rads downstairs and warm/hot rads upstairs. This was with all the TRVs open and the roomstat and boiler stat up to the max. The hotwater was fine.
The plumber said to check the header tank for water - I did and found that although it was full, the water was filthy and sludgy. He said that he thought it was likely to be the pump. As I have central heating cover I called out the company concerned. I explained the symptoms and they also said it was the pump, so this was duely replaced.
I ran the system for several days and bled the system as instructed ever couple of days however the problems remained.
I then suffered from boiler lockout problems which were resolved with a new PCB. The rad problems however continued.
As several more weeks had passed by, I was advised by the insurance company tradesman that I should drain down my system, add Fernox restorer and then drain/fill with clean water (after all the rinses inbetween!) and fernox inhibitor. He said that the difference between the flow and return pipes at my boiler was 35 deg C and it should be about 12 deg c and that there was obviously a flow problem (he then went on to try and sell me a powerflush at £400 but I declined)
I have ran restorer through the system on 2 separate occasions, both for a week at a time. I also scrubbed out the header tank until it was completely clean and free of sludgy water. I then repeated it as after the first dose I couldn't get the water to run clear despite filling and draining 6 times. After the second dose of restorer was run through I managed to get clean water, so then filled it with clean water and inhibitor.
This does seemed to have resolved my original problem, but I now have a new problem. This problem is that when the hot water circuit opens the downstairs rads either go cold or lukewarm - and the water now takes much longer to heat than before. Whats strange is that the pipes leading to and from the tank feel nice and hot. I wondering if I have a faulty tank thermostat but am not sure how to go about checking this. I have turned both of the tank thermostats up to see if it makes a difference, and the water is hotter but its not made any difference to the length of time it takes to heat or the rad problems.
I have checked all the bleed points (including the water tank points) but have not had any air since a couple of days after the final refill. I have also had all the rads balanced, as all the lockshields on the upstairs rads were fully open.
The last time I called the insurance company back out they said that I needed to get some sort of toning valve fitted to the hot water flow pipe so fix this problem. I've no idea what that is or how it might fix the problem.
I've tried to give as much info as I can (maybe too much) but I may have missed out some important detail - so apologies in advance.
I am at my wits end because as I write this there is several feet of snow outside and the house is once again cold. I'm having to rely on my immersion heater for several hours every days (yet it was never used before) and my gas fire in the lounge and expensive electric oil filled rads to supplement the heat when its as cold as it is tonight.
Many Thanks in anticipation
Duncan Thomson
I have a Potterton Suprima 40l Gas boiler, with a Santon Premier unvented hotwater tank. I have 12 rads, microbore piping, Grundfos 15-50 pump (running at speed 3) and a Lifestyle LP522 programmer. I bought my house new 4 years ago from Barratt.
There is a Drayton Roomstat (RTS 1 I think) in the Lounge and individual TRVs on all but 2 of the rads (1 upstairs, 1 downstairs)
There is also 1 Drayton ZA5 zone actuator (heating) and 1 Honeywell motorised valve (hot water)
The system was drained down in August last year to add some TRVs and thats when the problems began.
At the time of refilling no inhibitor was added to the system, although I didn't know about this until 2 months later when I called the plumber to ask why the heating wasn't working as well as it had been prior to the work. He casually mentioned at the time that he had meant to drop off a bottle of inhibitor for me to add to the system but he forgot!
The symptoms at that point were lukewarm rads downstairs and warm/hot rads upstairs. This was with all the TRVs open and the roomstat and boiler stat up to the max. The hotwater was fine.
The plumber said to check the header tank for water - I did and found that although it was full, the water was filthy and sludgy. He said that he thought it was likely to be the pump. As I have central heating cover I called out the company concerned. I explained the symptoms and they also said it was the pump, so this was duely replaced.
I ran the system for several days and bled the system as instructed ever couple of days however the problems remained.
I then suffered from boiler lockout problems which were resolved with a new PCB. The rad problems however continued.
As several more weeks had passed by, I was advised by the insurance company tradesman that I should drain down my system, add Fernox restorer and then drain/fill with clean water (after all the rinses inbetween!) and fernox inhibitor. He said that the difference between the flow and return pipes at my boiler was 35 deg C and it should be about 12 deg c and that there was obviously a flow problem (he then went on to try and sell me a powerflush at £400 but I declined)
I have ran restorer through the system on 2 separate occasions, both for a week at a time. I also scrubbed out the header tank until it was completely clean and free of sludgy water. I then repeated it as after the first dose I couldn't get the water to run clear despite filling and draining 6 times. After the second dose of restorer was run through I managed to get clean water, so then filled it with clean water and inhibitor.
This does seemed to have resolved my original problem, but I now have a new problem. This problem is that when the hot water circuit opens the downstairs rads either go cold or lukewarm - and the water now takes much longer to heat than before. Whats strange is that the pipes leading to and from the tank feel nice and hot. I wondering if I have a faulty tank thermostat but am not sure how to go about checking this. I have turned both of the tank thermostats up to see if it makes a difference, and the water is hotter but its not made any difference to the length of time it takes to heat or the rad problems.
I have checked all the bleed points (including the water tank points) but have not had any air since a couple of days after the final refill. I have also had all the rads balanced, as all the lockshields on the upstairs rads were fully open.
The last time I called the insurance company back out they said that I needed to get some sort of toning valve fitted to the hot water flow pipe so fix this problem. I've no idea what that is or how it might fix the problem.
I've tried to give as much info as I can (maybe too much) but I may have missed out some important detail - so apologies in advance.
I am at my wits end because as I write this there is several feet of snow outside and the house is once again cold. I'm having to rely on my immersion heater for several hours every days (yet it was never used before) and my gas fire in the lounge and expensive electric oil filled rads to supplement the heat when its as cold as it is tonight.
Many Thanks in anticipation
Duncan Thomson
