Words of wisdom gratefully received please!
I have a Vokera Maxin 24e combi boiler supplying 7 double radiators, one kitchen mixer tap, one bathroom sink mixer tap and one bath mixer tap with shower attachment. Boiler last had a major overhaul 9 years ago when I bought the property (it wasn't working at all) and was probably about 6/7 years old then. It's been periodically serviced since then, but not every year (naughty me).
Two days ago while I'm running the shower the boiler makes loud banging noise and all the water cuts out - hot and cold. I panicked, then switched the shower taps off, thinking it must be a water supply/pressure issue. I ran the bathroom sink cold tap (the one closest to the stop cock) - no problems. I ran the sink hot tap - no problems. I ran the shower again, no problems. Great. The following day I clean the house, which involves running quite a lot of hot water from both bathroom and kitchen taps - no problems.
But later that day I'm running the shower again - the bath mixer tap starts to vibrate loudly, the water spits violently and the boiler makes a series of banging noises. A long and painful diagnostic process ensues:
- If I run the cold only, from any tap including the bath/shower, there are no problems.
- If I run the hot from any of the sink taps, no problems, but it seems very hot.
- If I run the hot from the bath tap or the shower head (which is attached the mixer taps on the bath) it runs normally for a short while then the pressure drops dramatically down to a trickle, the boiler bangs and the hot water cuts out altogether.
- The hot works better and for longer if I only turn the tap on a little and the drop is pressure is more sudden the more open I have the tap
- It takes less time to go wrong the more I mess around with turning the hot water on/off, etc. and if I leave it alone for a while the hot water runs successfully for longer - at most this is only a couple of minutes though.
- The central heating is working normally.
- The pressure is normal - we have never had problems with pressure, needing to top the system up only once a year or so.
- None of the pipes are frozen - it's not cold enough here for that and I've checked the outflow pipe.
- We have very, very soft water so it's very unlikely to be limescale build-up - though could be a build up of sludge, etc. somewhere. The water here is so soft that we've had the same kettle for nearly ten years and there are no mineral deposits in it whatsoever (and I've never descaled it).
One other thing - for a long time (maybe 3/4 years) the boiler has had an intermittent problem where it locks out. The red lock-out light comes on, I press the button, the boiler re-fires, problem solved. This happens more in winter than summer and can happen when either heating or hot water is demanded. Very occasionally (one or twice a year) pressing the button doesn't solve the problem and I have to wait 5 minutes before pressing the button fixes the problem. We've had two heating engineers try to find a problem/solution when they've been round for a service - they couldn't see anything wrong.
Anyone any ideas what could be causing this?
In all honestly I can't see us forking out to repair this 15 year old boiler with undiagnosed intermittent problems so a new boiler is on the cards. But I'm concerned that the problem isn't being caused by the boiler and installing a new one will only leave us back where we started.
Any ideas at all would be welcome...
I have a Vokera Maxin 24e combi boiler supplying 7 double radiators, one kitchen mixer tap, one bathroom sink mixer tap and one bath mixer tap with shower attachment. Boiler last had a major overhaul 9 years ago when I bought the property (it wasn't working at all) and was probably about 6/7 years old then. It's been periodically serviced since then, but not every year (naughty me).
Two days ago while I'm running the shower the boiler makes loud banging noise and all the water cuts out - hot and cold. I panicked, then switched the shower taps off, thinking it must be a water supply/pressure issue. I ran the bathroom sink cold tap (the one closest to the stop cock) - no problems. I ran the sink hot tap - no problems. I ran the shower again, no problems. Great. The following day I clean the house, which involves running quite a lot of hot water from both bathroom and kitchen taps - no problems.
But later that day I'm running the shower again - the bath mixer tap starts to vibrate loudly, the water spits violently and the boiler makes a series of banging noises. A long and painful diagnostic process ensues:
- If I run the cold only, from any tap including the bath/shower, there are no problems.
- If I run the hot from any of the sink taps, no problems, but it seems very hot.
- If I run the hot from the bath tap or the shower head (which is attached the mixer taps on the bath) it runs normally for a short while then the pressure drops dramatically down to a trickle, the boiler bangs and the hot water cuts out altogether.
- The hot works better and for longer if I only turn the tap on a little and the drop is pressure is more sudden the more open I have the tap
- It takes less time to go wrong the more I mess around with turning the hot water on/off, etc. and if I leave it alone for a while the hot water runs successfully for longer - at most this is only a couple of minutes though.
- The central heating is working normally.
- The pressure is normal - we have never had problems with pressure, needing to top the system up only once a year or so.
- None of the pipes are frozen - it's not cold enough here for that and I've checked the outflow pipe.
- We have very, very soft water so it's very unlikely to be limescale build-up - though could be a build up of sludge, etc. somewhere. The water here is so soft that we've had the same kettle for nearly ten years and there are no mineral deposits in it whatsoever (and I've never descaled it).
One other thing - for a long time (maybe 3/4 years) the boiler has had an intermittent problem where it locks out. The red lock-out light comes on, I press the button, the boiler re-fires, problem solved. This happens more in winter than summer and can happen when either heating or hot water is demanded. Very occasionally (one or twice a year) pressing the button doesn't solve the problem and I have to wait 5 minutes before pressing the button fixes the problem. We've had two heating engineers try to find a problem/solution when they've been round for a service - they couldn't see anything wrong.
Anyone any ideas what could be causing this?
In all honestly I can't see us forking out to repair this 15 year old boiler with undiagnosed intermittent problems so a new boiler is on the cards. But I'm concerned that the problem isn't being caused by the boiler and installing a new one will only leave us back where we started.
Any ideas at all would be welcome...