Firstly - apologies if this is already covered elsewhere, I've been through the wiki and done a search.
I have a Worcester-Bosch Greenstar 40HE, professionally installed about 3 years ago and very reliable.
I also have an Aqualisa Visage digital shower, installed 18 months ago and working well in general.
My problem is this: about 1 time in 5 that the shower is used, the boiler ends up kettling and the shower (naturally enough) goes stone cold until the boiler cools down and resets itself. Examination of the boiler during this time shows the flow temperature to be way over 100 degrees, although DHW temperature never gets higher than it should.
The boiler NEVER kettles in any other circumstances, either for DHW or CH, only ever when the shower is used, and it always seems to be my wife that is under it when it happens. Typical.
The Aqualisa engineer said it was a boiler problem. I don't think he knew what he was talking about though, because he also said that rhythmic variation in shower pressure (high/low square-wave type cycling every 3 seconds) was a "boiler problem", even though there is no valve or DHW flow control in the boiler for it to be able to make that happen AFAIK.
The British Gas man who came to service the boiler last month said that there was nothing wrong with it. I wasn't there so I have no idea if he checked for sludge or anything like that. He dismissed concerns about kettling with some comment about the pump - of course, my wife couldn't remember wxactly what he'd said, but he still gave the thing a clean bill of health.
This problem was first noticed about 3 months ago and has steadily got more frequent, to the point that 4 out of 7 showers that my wife has had in the last week have gone cold (with the banging sounds of kettling).
We have good mains pressure and two supposedly fully working bits of equipment and yet it ONLY goes wrong when both are used together. I've not ruled out any of the usual suspects such as sludge, intermittent pump failure etc (especially as the problem is getting worse) but the fact that this problem only ever occurs when the shower is used is a bit baffling.
Do any of you knowledgeable types have any idea what may be happening here and what I should do to remedy it? Very grateful for any suggestions because, as you can probably imagine, the wife is on at me to sort it out
I have a Worcester-Bosch Greenstar 40HE, professionally installed about 3 years ago and very reliable.
I also have an Aqualisa Visage digital shower, installed 18 months ago and working well in general.
My problem is this: about 1 time in 5 that the shower is used, the boiler ends up kettling and the shower (naturally enough) goes stone cold until the boiler cools down and resets itself. Examination of the boiler during this time shows the flow temperature to be way over 100 degrees, although DHW temperature never gets higher than it should.
The boiler NEVER kettles in any other circumstances, either for DHW or CH, only ever when the shower is used, and it always seems to be my wife that is under it when it happens. Typical.
The Aqualisa engineer said it was a boiler problem. I don't think he knew what he was talking about though, because he also said that rhythmic variation in shower pressure (high/low square-wave type cycling every 3 seconds) was a "boiler problem", even though there is no valve or DHW flow control in the boiler for it to be able to make that happen AFAIK.
The British Gas man who came to service the boiler last month said that there was nothing wrong with it. I wasn't there so I have no idea if he checked for sludge or anything like that. He dismissed concerns about kettling with some comment about the pump - of course, my wife couldn't remember wxactly what he'd said, but he still gave the thing a clean bill of health.
This problem was first noticed about 3 months ago and has steadily got more frequent, to the point that 4 out of 7 showers that my wife has had in the last week have gone cold (with the banging sounds of kettling).
We have good mains pressure and two supposedly fully working bits of equipment and yet it ONLY goes wrong when both are used together. I've not ruled out any of the usual suspects such as sludge, intermittent pump failure etc (especially as the problem is getting worse) but the fact that this problem only ever occurs when the shower is used is a bit baffling.
Do any of you knowledgeable types have any idea what may be happening here and what I should do to remedy it? Very grateful for any suggestions because, as you can probably imagine, the wife is on at me to sort it out
