M
MartinT
My central heating system is well over 20 years old, but it's been working reasonably well until recently.
Firstly it seemed the 3 way value was getting stuck and sometimes there wasn't any heating. Switching CH/HW off and on seemed to fix, and so I replaced the Honeywell valve's head.
Then the upstairs rads were hot but the downstairs radiators were cold. The pump appeared to be working, but evidently wasn't as replacing that fixed the problem.
It was working fine for a couple of weeks, but now I've got a new problem, so they do appear to come in 3's!
When the heating first comes on there is a lot of load banging for the first 30 seconds or so- no alarm clocks needed in our household. It then goes quiet and works fine. The problem only happens when it has been off for several hours, and happens every time. It appears to be coming from the boiler and I think it is overheating as there is insufficient water flow. The boiler seems to start and cutout a few times before running constantly for 20+ minutes heating the house up. The radiators and hot water get hot and there isn't any air in the radiators. There is a bit of kettling noise, but no more than normal. In the past I've added the usual inhibitors and boiler noise chemicals.
I'm guessing it's a water flow problem, so have tried increasing and decreasing the pump speed but without any improvement.
Any ideas and solutions welcome, otherwise I'll need to get someone in.
Just to explain the setup; the Glowworm fuelsaver Mk2 boiler is downstairs, just below ceiling level, and there is a run of about 8 metres of pipe to the upstairs bathroom which is where the pump, 3-way valve and hot water cyclinder are. The header tank is also in the bathroom, just below ceiling level, and there isn't anything in the loft. 4 double panel rads downstairs and 2 large + 2 small singles upstairs. Other than on the radiators, there arn't any bleed valvess upstairs. There haven't been any pipework changes.
Thanks in advance
Martin
Firstly it seemed the 3 way value was getting stuck and sometimes there wasn't any heating. Switching CH/HW off and on seemed to fix, and so I replaced the Honeywell valve's head.
Then the upstairs rads were hot but the downstairs radiators were cold. The pump appeared to be working, but evidently wasn't as replacing that fixed the problem.
It was working fine for a couple of weeks, but now I've got a new problem, so they do appear to come in 3's!
When the heating first comes on there is a lot of load banging for the first 30 seconds or so- no alarm clocks needed in our household. It then goes quiet and works fine. The problem only happens when it has been off for several hours, and happens every time. It appears to be coming from the boiler and I think it is overheating as there is insufficient water flow. The boiler seems to start and cutout a few times before running constantly for 20+ minutes heating the house up. The radiators and hot water get hot and there isn't any air in the radiators. There is a bit of kettling noise, but no more than normal. In the past I've added the usual inhibitors and boiler noise chemicals.
I'm guessing it's a water flow problem, so have tried increasing and decreasing the pump speed but without any improvement.
Any ideas and solutions welcome, otherwise I'll need to get someone in.
Just to explain the setup; the Glowworm fuelsaver Mk2 boiler is downstairs, just below ceiling level, and there is a run of about 8 metres of pipe to the upstairs bathroom which is where the pump, 3-way valve and hot water cyclinder are. The header tank is also in the bathroom, just below ceiling level, and there isn't anything in the loft. 4 double panel rads downstairs and 2 large + 2 small singles upstairs. Other than on the radiators, there arn't any bleed valvess upstairs. There haven't been any pipework changes.
Thanks in advance
Martin
