Sparkies please! Wiring Hive to control Immersion Heater

Gaijin

Gaijin

Gaijin

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Joined
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Brighton/West Wicklow
Hi guys,

After installing my Hive for heating earlier this year, i'd now like to investigate getting it to control my hot water (immersion heater), which is a very common request which Hive have yet to provide a solution.

A lot of people wire their immersion heater into a Hive smart plug which does the job (if stressing the plug a bit) but it's not very elegant.

https://hivehome.uservoice.com/foru...ggestions/6912591-immersion-heater-controller

From doing a bit of research, a better way to do this is to use a adequately rated and installed solid state relay, so the Hive can do the low load switching and the relay can handle switching the 3KW load.

I want to present this idea to my electrician in an easy way that he'll understand (he's an older guy who isn't as familiar with smart home stuff).

So to the resident electricians, does the following diagram make sense?:

FBaqSZ8.jpg.png
 
Hi @rexehuk, myself and my electrician rigged this up as a proof of concept using a Schneider 25A relay and it works great. The only slight question mark was that sometimes it took a little while for the switching to happen. The Hive green light would flash every other actuation for about 30 seconds before switching the immersion on. I don't think it's anything to be worried about though but i'll monitor it.

I haven't installed this permanently however. The timer it is replacing sits in a rather ugly fashion in the middle of a utility room wall and so we need to mount the relay, run the wiring tidily and safely and relocate the timer wiring on the other side of the wall to where it is which is an airing cupboard. That's for another day.

Hope this helps.
 
@Gayjin that sounds great. I take it you've just wired it up to the general hw demand though so boiler kicks in plus immersion all the time Vs just boost mode?
 
I've wired it so that the hot water controls on the Hive just controls the immersion - the heating part of the Hive controls my oil boiler. Does that make sense?
 
Gayjin said:
I've wired it so that the hot water controls on the Hive just controls the immersion - the heating part of the Hive controls my oil boiler. Does that make sense?
Click to expand...

Ah I understand now, we have different systems.

My boiler does ch and hw, tank also has immersion on 16 amp dp switch.

Looking really to hit boost on tank, and it triggers the immersion to heat water super fast in combination with boiler.
 
Bit of a necro but just mulling over a modification - as sometimes, the hive doesn't appear to be switching on the immersion when it should.

My electrician will be swapping out the SSR with either another one or a contactor, but I've been wondering whether it's worth getting him to wire in an override switch at the same time (Either a simple switch or a "boost" timer).

Is this just a matter of wiring in another switched live from the supply or would the SSR need to be isolated before using the override switch (I.e. it won't damage it etc.)? He's coming next Monday after he gets back from holiday so just want to understand it before he turns up and obviously don't want to bother him on holiday.

gK6gOh4.jpg


Thanks!
 
The hive installation manual says that the permanent feed should come from a switched , both live and neutral , fused 3amp, spur.
How is this met, as the supply /mcb will be at least 15amp?
 
davib said:
The hive installation manual says that the permanent feed should come from a switched , both live and neutral , fused 3amp, spur.
How is this met, as the supply /mcb will be at least 15amp?
Click to expand...

The 2 circuits remain separate, the 3A circuit controlling the 15/16A circuit but they aren't electrically connected
 
HardwareGeek said:
The 2 circuits remain separate, the 3A circuit controlling the 15/16A circuit but they aren't electrically connected
Click to expand...
My understanding is that the permanent live(brown) & neutral(blue), for the hive reciever, are connected directly to the junction box which is between the supply and to the immersion element via the SSR and no other connection, as the diagram shows.

I cannot see a seperate 3 amp connection.
 
Diagram should show 2 desperate supplies 1 3A for the Hive and 1 15/16A for the immersion guess its just been simplified

The Hive just tells the contactor to turn the switched side on or off but the circuits are kept electrically separate
 
HardwareGeek said:
Diagram should show 2 desperate supplies 1 3A for the Hive and 1 15/16A for the immersion guess its just been simplified
Click to expand...

I drew the diagram above - Hardware geek is correct. In my instance, the hive receiver is 3 metres away from everything else and has it's own supply.
 
Not sure how the current IEE regs deal with circuits with seperate sources and isolation, but considor these, very unlikely but possible scenarios

1 Lady of the house checking the airing cupboard, discovers smoke coming from the contactor box, immediate reaction, switch off the immersion, this has no effect because it is the solenoid coil that is overheating, what now?

2 10 years on and a new house owner notices that the immersion heater is not working, switches off at the consumer unit, he removes the contactor cover, probes around with a screwdriver, hive calls for heat, oh dear, does he survive?

Things have moved on and thier are better, safer methods to use, that don't require a rewire job, eg a standalone unit, wifi, includes isolator and fuse, controlled by its own app for about £47.
 
Looking at the diagram above, I'd echo what others have said about the controls/oil boiler side being fused separatly at 5A. I'd impliment the override on the control side, rather than the load side. To cover possible issues from David's post, label the contractor enclosure along the following lines
Code: 
Warning: ------Multiple supplies------
Isolating water heater supply leaves
control supplied from boiler controls live
 
Bit of a necro but it's all relevant.

The Schneider solid state relay appears to have died over the last week or so, so may give an indication to those who were wondering whether an SSR or contactor would be best suited. It lasted 2 and a half years in the end. I've decided to go with a contactor this time around to see how they compare, even though the SSR failure might be an abnormal incident. I did notice some that the SSR did not like to be switched more than once in quick succession. I noticed that say if the immersion was on, and we had to re-boost it, it wouldn't do so immediately. It would take a little while to re-trigger. Will be interesting to see how it goes.

Also, I missed the last two posts - very valid and i'll be taking action even though this house will likely be ours until one of us pops our clogs.

Also noted re: the control side override - the only issue I'd have with this (if I understand you correctly) is that the primary reason for having the override at all, was in case of an issue with the SSR. Having it wired on the load side has allowed us to continue to have (albeit a manual 30/60/120 min Horstman boost control) a functioning immersion. Because the SSR is now faulty - had we wired it on the control side, we would have no backup solution.
 
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