Hive dual zone

[Blimster]

I have been asked to fit a hive multizone thermostat system on to a dual zone central heating setup..

The components are...
Logic heat 12 boiler
Honeywell st9100c single channel controller
Honeywell cm07 wireless stats..

Looking at the current wiring (see below), it appears theres only one switched live? I was expecting x3, one each for zones 1&2 + hot water..

So do these stats talk directly to the boiler somehow?

Is it going to be possible to install hive multizone on this set up?



Thanks in advance..

 

[Lister1987]

I'm not usually one to link to other forums but try this thread; Replacing Dual Zone Honeywell with Hive - https://www.diynot.com/diy/threads/replacing-dual-zone-honeywell-with-hive.506224/

Looks like they were trying exactly the same as you.

 

[StephenRowley]

Ignore what I said earlier it was rubbish.

Most likely but you need to check for sure the

Honeywell st9100c is the hot water timer

Honeywell cm07(do you mean cm707) are not wireless there wired combined room and timers. I take it there two of them one for each zone?

Which exact hive kit have they got? Two thermostat unit or single one?
[automerge]1576171091[/automerge]
As the hives are battery powered I would abandon the wiring to the timer and two combined room thermostat timers and just wire the hive receivers stright into the wiring center.

 

[Blimster]

Hi guys thanks for the prompt reply..

Oh i mistakenly thought the cm 707 was wireless because there were batteries..

The wiring centre is a serious mess on this one, but i suppose thats an option..

Can the hive receivers replace the 707's? If they are hard wired..

The customer has purchased a dual zone kit with x2 receives, x2 stats and a hub..

P.s i dont usually touch central heating wiring, its all new to me.

 

[EricMark]

I like the Hive system, it allows the boilers in built controls to monitor the return water temperature and so modulate the boiler, it does not need to be connected to the boiler ebus.

However the whole idea is every Hive TRV head is a zone, if any of the programmable heads demand heat, then the Hive wall thermostat will run the boiler.

So what is the point in zoning zones? Personally I would connect a duel Hive wall thermostat so the CH part opens all CH zone valves, and the DHW opens the hot water zone valve, and the TRV heads can do their job.

Without the TRV heads linking to Hive, it is rather useless in most houses, an on/off wall thermostat has two jobs in the main, easy assess switch to turn heating on/off, and a any cycling device to auto turn off heating on warm days, so why would anyone fit two, that's like having a RCD feed and RCD they are both doing the same job.

The idea was to zone houses so bedrooms could be divided from living rooms, that is OK when bedrooms are only used to sleep in, as soon as it is used for children to do home work in, it fails.

So this house over night all rooms at 17 degrees OK could set lower, could set to 10 degrees C, but lower it goes, longer it takes to warm up, so 8 am (we are retired) bedrooms set to 20 degrees C, however other upper floor rooms, office and craft room remain at 17 degrees, at 9 am the kitchen and dinning room are heated, and bedrooms switch back down, at 10 am living room switched up, dinning room back down, at 4 pm dinning room back on until 8 pm at 9 pm bedrooms go back up, at 11 pm all rooms down to 17 degrees.

Two points, one is every room individually controlled, second no room switched off, they are switched down, to do that the zone valve must modulate i.e. turn up/down, not off/on, it is OK to turn DHW off/on but not central heating, you want all controls to modulate.

OK there is a problem, the gas boiler will not modulate to zero, so you reach a point where it has to cycle, and you don't want it to cycle all summer long, so some where you want a thermostat that will turn it off in warm weather, but you don't need two thermostats.

OK there will be exceptions to the rule, I have a flat under the house heated by same boiler, since 95% time flat is only used for storage I do have a zone valve to turn off flat.

So in this house, thermostat turns zone valve on/off, zone valve turns pump and relay on/off relay turns boiler on/off, if I did not have two pumps, I would not need relays.

Idea is zone valve must open before pump can run, and pump and zone valves must be open/running before boiler starts, and one zone valve working will not trigger the pump on the other system, which is why it needs relays, so flat calling for heat will not cause any heat or pump to run for house.

So two up two down house OK zone valves, but zone valves cost around £50 each, so for extra £100 every room is independent, so why would anyone in their right mind use zone valves on two up, two down?

But I could be wrong, I never expected a conservative government but we have got one.

 

[StephenRowley]

If you feel uncomfortable doing it the naturally I would ask someone else who more experienced but

Hi guys thanks for the prompt reply..

Oh i mistakenly thought the cm 707 was wireless because there were batteries..

The wiring centre is a serious mess on this one, but i suppose thats an option..

Start over again wouldn't be too difficult. First confirm it wired to the usually standard or at least correct to it. The 2nd heating two port valve will be wired the same as the other two with the exception of the brown going into terminal 7.

Room stat and programmer in image go bye bye




On your two channel heating it'll want a LNE from wiring center.

terminal 4 would go to stright to terminal 5 in wiring center

Terminal 3 on two channel reviver goes to terminal 6 on the wiring center

On the second receiver it'll want LNE with terminal 3 going to terminal 7 on your wiring center.

Source URL: Hive dual zone - https://www.electriciansforums.net/threads/hive-dual-zone.181332/#post-1594540
Can the hive receivers replace the 707's? If they are hard wired.

You could be presumably there both in rather prominent positions and customers may not fancy it.

 

[Grant webber]

As above. Just remember to link L to terminal 1 on the single channel reciever also.

 

[Leesparkykent]

Install the receivers above the wiring centre, ditch the wiring to the existing thermostats and single channel programmer. The receivers just need powering, and the browns of each two port connecting to the corresponding terminals.

 

[EricMark]

The thermostats power the brown wires on the motorised valve 5 and 8 on wiring centre on flameports diagram, you will have three brown wires as three valves, so 3 and 4 from duel and 3 on single go to the three brown wires, with a link in the single thermostat, and of course power to both.

However I would only use the duel Hive and power both motorised valves from same thermostat, as the Hive TRV heads will form the zones, the zone valves are not required when using programmable TRV heads, but as an electrician easier to leave them in place and just open both together.

 

[StephenRowley]

That's presuming the customer going to swap all there TRV with hive ones.

 

[EricMark]

There are a number of smart thermostat systems, Hive, Evohome, Tado etc all which use the info from the TRV to control the boiler, without the TRV head that links they don't work that well, they rely on the connection to work well.

Nest seems to be the odd one out, to start with they worked with Energenie MiHome TRV heads, but it seems this partnership has now ended so the follow command does not work any more, it seems Hive was forced to introduce their TRV heads to comply with some laws, not sure which country to comply with control of individually areas, I expect Nest will soon market their own TRV heads to comply.

There seems to be a problem in the UK with the "Approved documents" not actually being correct in the way they interprete the law, and this is made worst with Wales and England not being the same. So we move into the let the courts decide, however unlikely to be any court case, so we have to do our best for the customer, working around the law best we can.

So idea of the zones was good, practice it fails in many ways, the main failure is the boiler is analogue, it has a variable output, the TRV is analogue it varies the flow it does not switch it on/off, and between them they will allow the boiler to gain the latent heat and put as little energy as possible up the flue.

But the motorised valve switches on/off, and every time you switch a boiler off there is energy in that boiler which can only be dispersed out of the flue, if the water stops flowing then the heat can't go into the house.

The three port valve was good in it's day, it allowed thermo syphon to remove the heat from the boiler and put it into domestic hot water after all power had been removed, the two port valve can't do that.

 

[StephenRowley]

Controlled TVR in ever room is nice in theory but not many are going to willing to spend 60ish quid a room.

 

[123]

Controlled TVR in ever room is nice in theory but not many are going to willing to spend 60ish quid a room.

And a lot more if the existing TRV doesn't suit the new head, or if there isn't one already. And they look terrible on any fancy radiators.

 

[EricMark]

Controlled TVR in ever room is nice in theory but not many are going to willing to spend 60ish quid a room.

I have 9 programmable TRV heads 4 MiHome and 5 eQ-3 the latter were £15 each and non bluetooth down to £10 so costs are not that high.

 

[Leesparkykent]

I have 9 programmable TRV heads 4 MiHome and 5 eQ-3 the latter were £15 each and non bluetooth down to £10 so costs are not that high.

They aren’t Hive though are they?