<div class="bbWrapper">Have client with above 18 month old boiler. She says she has difficulty in getting it to produce hot water, heating works fine. However, every time I turn up (four times now) it works fine. Diverter pin hits micro switch, pump runs, fan comes on, burner lights. I appreciate intermitant faults are difficult to diagnose, but has anybody else come across this problem?</div>
Alpha CB28 Problem
- Thread starter avidfan
- Start date
<div class="bbWrapper">Please ignore the above ChrisR, it's the horseshoe clip on the diverter valve. Mind went blank. Thanks anyway. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f633.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":oops:" title="Oops! :oops:" data-smilie="10"data-shortname=":oops:" /></div>
<div class="bbWrapper">Its alright, I did not really understand that either.<br />
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Chris is preoccupied genning up for his forthcoming visit to an Ideal Response with an intermittent CH operation! As it works fine on DHW it a bit difficult to immagine what could be the problem apart from the cheap switches on the front panel.<br />
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Tony</div>
<div class="bbWrapper">Well it has a <i>flow switch </i>which <i>clips on </i>- sorry I'm not sure which word you wouldn't understand!<br />
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Not actually busy genning up on a Response. I did ask Agile to send back the boards he borrowed from me when he was <i>unable to diagnose a fault </i>on a Response! <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f631.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":shock:" title="Eek! :shock:" data-smilie="9"data-shortname=":shock:" /> <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f631.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":shock:" title="Eek! :shock:" data-smilie="9"data-shortname=":shock:" /> <br />
Oh sorry he's always able to diagnose within seconds and never resorts to being a "parts changer" so surely it <i>must </i>have been someone else? (Maybe I shouldn't have said that or he'll stop helping me when I'm stuck.. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f606.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":lol:" title="Laugh :lol:" data-smilie="18"data-shortname=":lol:" /> )<br />
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"My" Response was reportedly failing reliably so I went today and spend an age trying to make it go wrong. It was a broken conductor inside a piece of flex under a ty-wrap <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite31" alt=":evil:" title="Evil Twisted :evil:" loading="lazy" data-shortname=":evil:" /> . Evidently you had to get exactly the right combination of swear words and physical abuse for it to show up.<br />
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(It could only be a Response, for the fault finding chart to tell you to check if the pcb is wet!!)</div>
<div class="bbWrapper">Its true that I was unable to diagnose a fault, however that turned out to be because there was no fault!<br />
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The problem was that the supply fuse to the fan PCB failed. As usual when testing I used a lower value fuse 1.6 A in this case in place of the original 3.2 A. The 1.6 A was blowing due to a massive overload and blew with a flash of white light.<br />
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Chris kindly sent me some boards from an old Response. I eventually noticed that the fuse on his boards was actually 4 A rather than 3.2 A. I concluded that they must have had a problem with the 3.2 A fuse blowing and uprated to 4 A to solve the problem.<br />
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Its difficult to measure initial inrush currents without a storage scope and the operation of fuses is an interesting although basic technology. Fuses blow in a timescale inversely proportional to the overload. I would say its questionable to use a fuse with such a high inrush as on that Response but having said that its not their most common failure point.<br />
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Tony</div>
