Hello,
Amateur newbie to the forum here ... trying desperately hard not to get stung for plenty of parts being unnecessarily swapped out to mend our slightly poorly boiler(!).
We own a Worcester-Bosch Highflow 400 (I believe it's the "RSF" version, although I thought it was simply a balanced flue - until I grabbed the "Installation and Servicing Instructions" which were labelled otherwise!). It's ill!
It was fitted by my wife's CORGI-registered cousin 7 years ago when we asked for a combi boiler with high-pressure (Yes! I know NOW!!!) for our shower and one which wouldn't go cool when other taps were turned on (yup, once bitten ... and all that!).
Notwithstanding, fortunately we've had no operational problems, despite it never having been serviced (we simply ran out of cash 6 years ago ... and I mean completely! We're not daft - or tight - just broke!).
However, when we turned on our heating timer for the winter this weekend, all ran OK for a few hours, until my wife attempted to run a large, hot bath (she does that! Often!!!). Up until then, we had hot water in the kitchen as demand required and the radiators were all hot from top to bottom. No untoward clunking, no gurgling, fast on-time, warm house!
Anyways, she got about half-way through running her bath when there was lots of mechanical thumping, clunking and gurgling (the boiler is installed in our loft, right above the bathroom, so we can readily hear all this), as the hot water flowing into her bath grew rapidly colder. And then the boiler shut itself off, radiators and all, with a loud thump and lots of noisy, metallic-like thudding and gurgling.
My little one thought we had an alien in the loft! Ah well, if only! He could’ve fixed my boiler.
Brief investigation showed the HW and CH lights to be flashing slowly, which the manual says indicates a "Safety Temperature Limiter lockout". This was simply reset by turning the CH temperature control off then on again.
However, I also noticed that there was absolutely zero pressure showing on the pressure gauge to the bottom, right-hand, front corner of the boiler.
I turned the (plumber-installed) external valve to allow water to enter the system and released it at just under 3Atm. I then vented the excess out, by turning the boiler's red "Relief Valve" to the top, left-hand, front corner of the boiler (as I had been shown by the Worcester-Bosch service engineer after our one and only check) until it showed just under 2Atm.
What happens now is weird:-
Obviously, after the second time this happened, I avoided it happening again. Currently we have to manually turn the CH off if anyone wants a bath or shower, however short.
Furthermore, I am having to 'top-up' the water pressure every couple of days. There is a miniscule water leak - literally drops - just by the plumber-installed water inlet valve I mentioned previously, but that's it! (Regardless, it's on the cold water inlet side, not the boiler side of the valve, so I think this is a coincidental red herring).
Whilst I GENUINELY don't mind spending the appropriate amount of money for a fully-qualified service and repair, I really do NOT want to pay to swap out each and every part as a process of elimination because our engineer has limited experience or is lacking in capability. So, what should I do?
From all that I've read, it seems Highflow 400s are not flavour of the month (and seldom have been, except for a few engineers), they're unduly complicated, have some weird componentry, a high failure rate for diverter valves and control PCBs, are expensive to service (especially by Worcester-Bosch) and are prone to the heat exchanger furring up in hard water areas (of which ours is one, damnit!).
I've also gleaned that the diverter valve is the likely culprit and that this has no serviceable parts and should simply be swapped (don't worry, I can't and won’t attempt this!).
However, any considered advice - or offer of a repair (we're in South Staffordshire) gratefully received.
Thank you for your time; if you need any further details, please respond to this thread (so others can raise their awareness of this particular issue) or PM me if you're shy.
Once again, thanks.
Steve & Kellie.
Amateur newbie to the forum here ... trying desperately hard not to get stung for plenty of parts being unnecessarily swapped out to mend our slightly poorly boiler(!).
We own a Worcester-Bosch Highflow 400 (I believe it's the "RSF" version, although I thought it was simply a balanced flue - until I grabbed the "Installation and Servicing Instructions" which were labelled otherwise!). It's ill!
It was fitted by my wife's CORGI-registered cousin 7 years ago when we asked for a combi boiler with high-pressure (Yes! I know NOW!!!) for our shower and one which wouldn't go cool when other taps were turned on (yup, once bitten ... and all that!).
Notwithstanding, fortunately we've had no operational problems, despite it never having been serviced (we simply ran out of cash 6 years ago ... and I mean completely! We're not daft - or tight - just broke!).
However, when we turned on our heating timer for the winter this weekend, all ran OK for a few hours, until my wife attempted to run a large, hot bath (she does that! Often!!!). Up until then, we had hot water in the kitchen as demand required and the radiators were all hot from top to bottom. No untoward clunking, no gurgling, fast on-time, warm house!
Anyways, she got about half-way through running her bath when there was lots of mechanical thumping, clunking and gurgling (the boiler is installed in our loft, right above the bathroom, so we can readily hear all this), as the hot water flowing into her bath grew rapidly colder. And then the boiler shut itself off, radiators and all, with a loud thump and lots of noisy, metallic-like thudding and gurgling.
My little one thought we had an alien in the loft! Ah well, if only! He could’ve fixed my boiler.
Brief investigation showed the HW and CH lights to be flashing slowly, which the manual says indicates a "Safety Temperature Limiter lockout". This was simply reset by turning the CH temperature control off then on again.
However, I also noticed that there was absolutely zero pressure showing on the pressure gauge to the bottom, right-hand, front corner of the boiler.
I turned the (plumber-installed) external valve to allow water to enter the system and released it at just under 3Atm. I then vented the excess out, by turning the boiler's red "Relief Valve" to the top, left-hand, front corner of the boiler (as I had been shown by the Worcester-Bosch service engineer after our one and only check) until it showed just under 2Atm.
What happens now is weird:-
-
The central heating works fine - super hot, super quick, super efficient.
The hot water works but ONLY when the central heating is off.
If the central heating is on, the hot water runs for a few minutes, then rapidly cools. Simultaneously, the pressure gauge valve goes down to zero, whereupon the boiler turns itself off and requires resetting (by the aforementioned CH dial procedure).
Obviously, after the second time this happened, I avoided it happening again. Currently we have to manually turn the CH off if anyone wants a bath or shower, however short.
Furthermore, I am having to 'top-up' the water pressure every couple of days. There is a miniscule water leak - literally drops - just by the plumber-installed water inlet valve I mentioned previously, but that's it! (Regardless, it's on the cold water inlet side, not the boiler side of the valve, so I think this is a coincidental red herring).
Whilst I GENUINELY don't mind spending the appropriate amount of money for a fully-qualified service and repair, I really do NOT want to pay to swap out each and every part as a process of elimination because our engineer has limited experience or is lacking in capability. So, what should I do?
From all that I've read, it seems Highflow 400s are not flavour of the month (and seldom have been, except for a few engineers), they're unduly complicated, have some weird componentry, a high failure rate for diverter valves and control PCBs, are expensive to service (especially by Worcester-Bosch) and are prone to the heat exchanger furring up in hard water areas (of which ours is one, damnit!).
I've also gleaned that the diverter valve is the likely culprit and that this has no serviceable parts and should simply be swapped (don't worry, I can't and won’t attempt this!).
However, any considered advice - or offer of a repair (we're in South Staffordshire) gratefully received.
Thank you for your time; if you need any further details, please respond to this thread (so others can raise their awareness of this particular issue) or PM me if you're shy.
Once again, thanks.
Steve & Kellie.
