Nest/Hive Advice

SweetCaliber

Hi all,

Looking to get a Nest/Hive for my house. I currently have a Potterton Performa 12HE gas boiler that handles the heating and hot water. I have two APT timers, one for the heating and one for the hot water.

I have a thermostat in the living room, and another in the main bedroom upstairs. Both of these seem to open and close the motorized valves in the hot press depending on the temp.

Question is, I am fairly sure this is a two zoned install, however I don't need two zones, I have both thermostats up to the max (30 deg) so is there a way to install a single nest/hive to control both hot water and heating (but have the heating just count as 1 zone ? )

Thanks!

DGOBS

As you stated, you only have 2 timers, so there is 2 zones (heating and hot water)

It sounds as if the upstairs/downstairs stats feed motorised valves without the auxiliary switches wired in to call the boiler (orange and grey wires cut back)

SweetCaliber

DGOBS wrote: »

As you stated, you only have 2 timers, so there is 2 zones (heating and hot water)

It sounds as if the upstairs/downstairs stats feed motorised valves without the auxiliary switches wired in to call the boiler (orange and grey wires cut back)

Thought so, thanks! So I take it setting both stats to max and then installing nest for heating and hot water shoukd work without issue ? Cheers

DGOBS

Yes it would (or you can have your installer link out both stats either)

xl500

If you have a Stat upstairs in main bedroom and a stat down stairs in Living room are both stats opening the same valve for the heating usually 2 stats would indicate 2 zones maybe timer switches on heating and stats control upstairs seperate to downstairs

A bit more info what the 2 stats are switching would help

DGOBS

In this type of setup stats are usually switching 2 separate MVs, but with no interlock to the boiler, generally you'll find the DHW is an open circuit or at best with a TCV, so even when all zones are satisfied the boiler short cycles.

xl500

DGOBS wrote: »

In this type of setup stats are usually switching 2 separate MVs, but with no interlock to the boiler, generally you'll find the DHW is an open circuit or at best with a TCV, so even when all zones are satisfied the boiler short cycles.

Yes Its just I thought when you said 2 Zones Heat and HW there was only one heat Zone with 2 stats

If there are 2 Heat Zones and 2 MVs for heat then wouldnt OP be better keeping 2 Zones going to single zone seems a backward step

SweetCaliber

xl500 wrote: »

Yes Its just I thought when you said 2 Zones Heat and HW there was only one heat Zone with 2 stats

If there are 2 Heat Zones and 2 MVs for heat then wouldnt OP be better keeping 2 Zones going to single zone seems a backward step

Yes essentially there are two stats, each control their own MV. Only one timer operates the heating and another operates the hot water (again its just another MV, I have a system boiler).

I understand what your saying, I am going backwards by only using one nest. However as said the stats only control the MV's. The programmer is a timer and essentially just tells the boiler to turn on or off, I'm unsure how two nests could be fitted into this mess in the future.

Hence, if I just get the stats removed, or set them to full, when the boiler comes on both MV's would open, and then when it goes off they will close again.

xl500

SweetCaliber wrote: »

Yes essentially there are two stats, each control their own MV. Only one timer operates the heating and another operates the hot water (again its just another MV, I have a system boiler).

I understand what your saying, I am going backwards by only using one nest. However as said the stats only control the MV's. The programmer is a timer and essentially just tells the boiler to turn on or off, I'm unsure how two nests could be fitted into this mess in the future.

Hence, if I just get the stats removed, or set them to full, when the boiler comes on both MV's would open, and then when it goes off they will close again.

Sure Both Valves will open but in the future would you really want Bedrooms on at the same time as Downstairs I would really look at keeping 2 Heating Zones if you could

DGOBS

Best would be run a 7 core cable from MVs to boiler, and install a new MV on the hot water and go for a multizone Hive setup, then you'd have all the control and interlock to the boiler.

batman2000

I am also interested in the Hive.
I've a quick question.
I have a APT analogue timer beside the boiler to set the on/off time
I have a thermostat on the wall.
In the summer, i turn this to zero and the motorised valve turns off the heating and the boiler heats the hot water instead.
I do not have heating control for upstairs or downstairs.

Is my system a 1 zone or 2 zone system.?

Thanks,

DGOBS

Essentially your system is neither! (in the sense of S-plan wiring systems) its somewhere in-between.

What I have done with Hive when i have encountered these system is this:

Install a Hive Dual Channel (Heating and hot water) when wiring, if behind the timer thats being replaced, there is the live that is powering your thermostat (it's there in most cases) I use that on the channel for central heating, and the boiler switched live from the timer, is used for the hot water channel.

When install is complete, set the receiver into 'gravity mode' (hold the hot water button for 10-12 seconds until the green light at the top turns blue)

So what happens not is, when you select hot water, the hot water channel powers the boiler, but the is no power to the old thermostat (which not needs to be linked out of the system) and the boiler just fires to hot water.

When central heating is selected, power goes on both channel in gravity mode, so hot water comes on to power the boiler, and central heating comes on to power the motorised valve that the old thermostat used to control.

The great thing about this now is, from your Hive stat and your phone you can now have an independent timer for hot water only that you didn't have before!

The draw back, is when you have your central heat on, you will always heat the hot water at the same time, required or not!

batman2000

DGOBS wrote: »

Essentially your system is neither! (in the sense of S-plan wiring systems) its somewhere in-between.

What I have done with Hive when i have encountered these system is this:

Install a Hive Dual Channel (Heating and hot water) when wiring, if behind the timer thats being replaced, there is the live that is powering your thermostat (it's there in most cases) I use that on the channel for central heating, and the boiler switched live from the timer, is used for the hot water channel.

When install is complete, set the receiver into 'gravity mode' (hold the hot water button for 10-12 seconds until the green light at the top turns blue)

So what happens not is, when you select hot water, the hot water channel powers the boiler, but the is no power to the old thermostat (which not needs to be linked out of the system) and the boiler just fires to hot water.

When central heating is selected, power goes on both channel in gravity mode, so hot water comes on to power the boiler, and central heating comes on to power the motorised valve that the old thermostat used to control.

The great thing about this now is, from your Hive stat and your phone you can now have an independent timer for hot water only that you didn't have before!

The draw back, is when you have your central heat on, you will always heat the hot water at the same time, required or not!

Thanks, I should edit my "quick" question.
That sounds fine. Currently, when the central heating is on, the water is heated also.

DGOBS

Sorry, just wanted to give you a 'full' answer to that one, incase you need to engage with a Hive installer.