Hi all,
My customer's f&e tank overflow has had a steady trickle. When the hot water is turned on, it gushes.
I initially changed the ball valve (shutting off perfectly) and stiffened the side of the tank (it was flexing out, but otherwise been in for years with no issues), then realised the excess water was coming up the feed pipe.
When calling for hot water only, the heating pipe flow from the 3-port valve was burning hot. So that's been changed. But in retrospect, that wasn't the cause of the problem.
More investigation - the circulating pump was definitely knackered. So that's been replaced. I drained the system, so I could also replace the 'original and corroded' gate valves on the pump, and flush out the dirty central heating water and re-fill with inhibitor. No trickle from my open pipe ends once drained, so it can't be the coil in the cylinder. Cylinder immersion is turned off (hasn't been used in 30 years).
But still a steady trickle from the overflow pipe.
The boiler is a wall-hung old Thorn, with a flow, return and also a vent pipe connected to the boiler. The feed pipe is teed on to the return pipe.
When the boiler is fired up, on hot water only, the pipes and boiler casing get very, very hot. I suppose it would eventually reach similar temperatures on the central heating circuit, given long enough.
I suspect the issue lies with the boiler, and possibly a boiler stat has gone.
The main temperature stat knob on the front of the boiler seems to work - when turned down to 1, the burner goes out. But I'm supposing (I'm not familiar with this particular boiler), that there is a high and lo stat in there as well, to monitor flow and return temperatures.
The boiler has a permanent pilot light. Even when there's no demand for hot water (they're not using it until it's been fixed, and so the pump hasn't been running or pumping over), there is a steady trickle from the overflow. The flow pipe is tepid. Surely expansion from just a pilot couldn't produce so much water overflowing?
British Gas are going out tomorrow to check out the boiler (it's under one of their service plans).
Any ideas anyone?
Jennie.
My customer's f&e tank overflow has had a steady trickle. When the hot water is turned on, it gushes.
I initially changed the ball valve (shutting off perfectly) and stiffened the side of the tank (it was flexing out, but otherwise been in for years with no issues), then realised the excess water was coming up the feed pipe.
When calling for hot water only, the heating pipe flow from the 3-port valve was burning hot. So that's been changed. But in retrospect, that wasn't the cause of the problem.
More investigation - the circulating pump was definitely knackered. So that's been replaced. I drained the system, so I could also replace the 'original and corroded' gate valves on the pump, and flush out the dirty central heating water and re-fill with inhibitor. No trickle from my open pipe ends once drained, so it can't be the coil in the cylinder. Cylinder immersion is turned off (hasn't been used in 30 years).
But still a steady trickle from the overflow pipe.
The boiler is a wall-hung old Thorn, with a flow, return and also a vent pipe connected to the boiler. The feed pipe is teed on to the return pipe.
When the boiler is fired up, on hot water only, the pipes and boiler casing get very, very hot. I suppose it would eventually reach similar temperatures on the central heating circuit, given long enough.
I suspect the issue lies with the boiler, and possibly a boiler stat has gone.
The main temperature stat knob on the front of the boiler seems to work - when turned down to 1, the burner goes out. But I'm supposing (I'm not familiar with this particular boiler), that there is a high and lo stat in there as well, to monitor flow and return temperatures.
The boiler has a permanent pilot light. Even when there's no demand for hot water (they're not using it until it's been fixed, and so the pump hasn't been running or pumping over), there is a steady trickle from the overflow. The flow pipe is tepid. Surely expansion from just a pilot couldn't produce so much water overflowing?
British Gas are going out tomorrow to check out the boiler (it's under one of their service plans).
Any ideas anyone?
Jennie.