Sharky 775: E-4 Hardware error in ultrasonic measurement

Anyone ever seen E - 4 error on Sharky 775 or know if there is anything that can be done to diagnose or resolve this? According to the manual this error is caused by the following, but both the flow meter and the heat meter are sealed.

Hardware error in ultrasonic measurement

  • Ultrasonic transducer defective
  • Short-circuit in ultrasonic transducer

This heat meter was working when it was installed 2yrs ago, but now I’m finally hooking it up to my home automatiom I see that it reports this error and won’t give me flow rate or power. Since then nothing has changed installation-wise, so it’s a bit weird.

@marko you have any ideas?


Usually caused by the plumbers wrapping the cable around the flow sensor then straining it when tightening fittings. Or by having it hanging between flow sensor and calculator mounted to fix locations then standing on it.

Pull battery, wiggle the cable, replace battery, and see if error clears?

I think this is what must have happened, no other explanation other than premature failure which is unlikely. :frowning:

I’ve tried reseting it, wriggling cable etc but no luck. I also opened up the calculator to check connections to the PCB were sound and that there wasn’t a short in the cable, but this is all good. So it must be an issue with the connection into the flow meter which as far as i can see, isn’t accesible.

Looks like I’ll have to shell out for a new one…


You can also be cheap.

If it were temperature probes those need replacing in matched pairs.

Flowrate sensors are more meh. Break open the plastic outer assembly. (screws under the quality stickers perhaps?) The wiring to the flowrate sensors is coax. You can do a cut and shut on that without ballsing up the calibration for practical purposes. No longer MID but saves getting wet swapping it. Disconnect battery first. Worst case signals get a little noisier and it trips out earlier on air/dirt. It won’t affect time-of-flight measurement or the calibration of that specific flow sensor assembly for manufacturing tolerances that are coded into the matching calculator.

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I mistakenly thought the flow meter unit was sealed and because it’s not particualry accessible hadn’t investigated further. You are right though, and the cover comes off and connections are visible.

On inspection there is no visible damge, the soldered connections are sound, there are no shorts and there is continuity between the flow meter and the calculator. So I’m a bit lost as to what the issue might be. Is there any way to reset the calculator, or it’s just a case of removing power for a while? How can I tell is the transducer is working, can I measure anything to determine this?

I screwed up and fiddled with the white insert which promptly shot out and I couldn’t find, so I managed to flood the plant room! Finally found it and everything back together now, but I’ll need to wait a few days for mains-powered Sharky to dry out from any splashes before having another look at this.

If you have continuity on the cable and none between conductors I guess that rules out having stood on it.

I’m unsure what else might cause an E-4 error. You mention mains power. I don’t think a dad coin cell can cause an E-4 but perhaps that’s worth a try. Water shorting across sensor connections? Moist dead spiders? Metal grinding dust from your father building metal stuff in the shed / living in Sheffield etc?

The 775 is usually a VERY reliable unit. (the most reliable on the market I’d say; at least in our operational experience)

Not sure what the white insert that you describe is. (been years since I dismantled one of these sorry) Sorry if I just advised you to pull a cover that was retaining some kind of bung and flooded your plant room as a consequence. Not cool. Not deliberate! :-o

Weird stuff can also happen sometimes. Here’s a Zenner C5 where the packing between the transducer and the brass body has failed internally and it’s leaked past the transducer then up through the cable (not coax on these; just 4-core) and filled up the calculator!

The composite units (Landis T230, Axioma E4) can’t do this as the transducers “look through” the glass filled plastic flow sensing element rather than having transducers sealed into brass housings with glanding.

No, this was 100% my fault. Removing the cover didn’t remove the bung, I was me fiddling that removed it!

Looking at the connections more closely I can see that there are two co-ax’s , and it’s not just two cores. So it looks like I only tested the screening for continuity on both of these and didn’t even consider the inner conductor! Once things dry out I’ll take another look, but I’m assuming I’ll find that the inner conductor is broken on one of them, or has become unsoldered.

Best bet will be to try to find some repleacement cable and re-terminted on both ends. Not sure how easy it’s going to be easy to find it though…

I should still have considered that being a possibility sorry.

Agree that a broken internal coax is likely; typically where strain relieved. You can shorten these cables without issue. I’d keep chopping until you find a good bit in the same way you might a power tool cable broken at the plug/strain relief on the tool. :slight_smile:

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Had one go at soldering but still e-4. Could well be my soldering skills though as soldering really thin co-ax in a fairly inaccessible location is a challenge! Will try to have another go today. Trying to work out if I can fix it or need a replacement before I have ASHP service done, in case I do need to replace it.

No luck re-wiring, even though I’ve resoldered and checked for continuity and shorts mutlipe times and am sure that the connections are sound and cable is good. So, either I damaged something during soldering, or there is an issue with the flow-meter. I’m not sure how, if it’s even possible, to test the flow meter with a multi-meter though.

Was worth trying, but looks like I’m going to have to drain UVC and switch it out if I want DHW data in home automation as I’d planned. Out of warranty, so might see if I can pick one up on eBay or something.

DOH! Worth trying. :frowning: