Another faulty Nest "heat link"
Added 2022-01-08 00:18:29 +0000 UTCThis time I'm showing a couple of external tests that can be done. I also removed the faulty component using the two soldering iron tweezer technique.
https://www.youtube.com/watch?v=-2XxO1_mFdE
I've got some other diodes on order to check out. The original package is called a Powerdi package. The diode I fitted is only rated for 60V versus the original 100V one. It should probably be at least the same as the original. Sourcing the diodes from prominent local retailers is proving difficult due to stock issues.
Comments
Now I'm back home - the rated charging current of the 'remote' unit is 100mA, so well within the capabilities of a 1A diode. Of course you do have the potentially long cable run to think about as well (in my case, its re-purposed mains cable as I re-used the old wired thermostat wiring).
Mark Gray
2022-01-12 22:38:53 +0000 UTCI've not traced the tracks for the 12V. I doubt they'd use a series resistor, as the external unit could draw a reasonable current.
Big Clive
2022-01-08 18:21:58 +0000 UTCUnfortunately to do a proper test I need the other part of the unit, which is run from the 12V bus. When I fixed the last one, the UF4003 diode I put in didn't show much warmth at all with both relays energised.
Big Clive
2022-01-08 18:21:05 +0000 UTCIs there a series resistor between the outside world and the diode? Also does shorting the 12V blow the diode? If so a low value series resistor may help it survive. An altenative is as you stated a large voltage spike coming back up the wires.
Tokkan FX
2022-01-08 17:52:30 +0000 UTCHaving fixed it, the only thing I would check is the temperature rise of the new diode against a reference unit.
Mike Page
2022-01-08 16:40:46 +0000 UTCYeah. And this was caused by one company that is basically a marketing company that presents itself as if it's an official government body.
Big Clive
2022-01-08 15:38:24 +0000 UTCGiven the number of warranty returns I'd say they're painfully aware of the situation.
Big Clive
2022-01-08 15:37:31 +0000 UTCA great follow up video, and interesting that it is the same fault as before. I wonder if Google (Nest's owner) are aware?
Jon Knight
2022-01-08 13:52:51 +0000 UTCIt would be amazing if you could become an electrician in a week I can't even complete all my College electrical classes that are required to become an electrician in a week let alone the 8000 hours of apprenticeship that is required before I can take my journeyman test what a joke
Jonathan Hughes
2022-01-08 09:21:51 +0000 UTCI think they were playing safe. It's got be worried enough to order some diodes with a higher voltage rating.
Big Clive
2022-01-08 07:03:13 +0000 UTCFor those curious as to the Godfrye's Corps Maker... I offer the following recipe: 3 ounces (90 ml science) Gin, something very light with prominent citrus notes. 1 ounce (30 ml) a nice rye or good quality Polish potato Vodka. 1/2 tablespoon (0.5 ml) quality purchased, or homemade Grenadine syrup. 3 to not more than 4 drops (to taste) Angostura bitters. 1 mini-ice cube (weight near'about 0.4 ounce (11 grams). Allow the ice to near'about fully melt into the drink while occasionally stirring, enjoy a most tasty adult libation!
Mustafa's Fleas
2022-01-08 06:08:56 +0000 UTCThe wonderious new technoledgy has become the trap. All hail and purchase the marvels of the latest techno'magical wonders (or IMHO: craptastic shite)!!! I, Ludite #1, am left unconvinced that actual real progerss has yet to be acheeved. E'ffit! I'm mixing up another Godfry's Corpse Maker then going to bed!
Mustafa's Fleas
2022-01-08 05:45:53 +0000 UTCI still love a nice relay. I have loads I've recovered from equipment. They always have that pleasing click.
Tony Weavers
2022-01-08 03:02:37 +0000 UTCnaw, definitely not. it's a nice indication that something is actually occurring
Myriad
2022-01-08 02:18:38 +0000 UTCI'm sorry, stupid comment but am I the only one who finds the click of a relay inexplicably pleasing?
nowt
2022-01-08 01:21:38 +0000 UTCI know there's no such thing as a stupid question but I might have found one... Would the rating of the replaced diode be higher than expected because the external 12v device usually has a long cable run? (assuming boiler to remote is usually quite far on slim cables)
Sog Sussex
2022-01-08 00:42:56 +0000 UTC
