Hot water function

[FuManchu]

Hi,

I'm currently on an oil system, that when on heats both the radiators and hot water tank, it's not separated. I'm trying to figure out if it's possible, can i set up the hot water function on the nest that is literally just turning the whole system on for X minutes.

I'm planning for the summer months when radiators will be switched off. I want to be able to schedule the system to come on so I have hot water in the mornings without having to schedule via a temperature setting like I currently have to.

30 mins is more than enough and the current set up only allows hourly schedules and only comes on if the room is lower than what the schedule is set. Feel like during the summer I'll currently need to set the schedule to a high temperature to ensure the system turns on at all and then due to the radiators being off its going to be on for a full hour.

I went to the nest Pro settings and added the water on/off but using it doesn't seem to trigger anything. Does this sound like my heatsync needs rewired as is possibly missing wiring in the call for water connections?

Thanks 

[Paul_R]

Hi there, thanks for reaching out! Could you please tell me more specifically what kind of boiler you have? I assume it is a system boiler since you have a Hot Water tank, but I want to be sure. Could you please also send me a picture of the wiring of the Heat Link? You'd find it if you take the cover off.

[FuManchu]

Hi Paul,

Yes it's a system boiler with hot water tank.

Picture of the wiring attached.

Thanks

Liam

 

[OannaCG]

Thanks for the picture! Please click here to see the installation guide; there you can find examples for both S plan and Y plan for the system boiler with the hot water tank. 

[FuManchu]

Thanks for this, the S plan and the Y plan seem to assume I either have separate valves so could control hot water and heat separate or a zone. Which I don't.

This system when it's on, supplies heat to both radiators and hot water tank, you can't chose to heat one or the otger. I know if I could get the call for hot water function working it would also supply heat to the radiators but during the summer being able to call for 30 mins of heat while the radiators are off at their valves is more than enough for a shower etc.

[AlexD]

Understood. When using the hot water control side in the Nest app or from the thermostat itself, boosting the hot water engages the relay located in terminal 4/5/6. This is why boosting the hot water has no effect, the relay may be engaging but there are no wires in those terminals. The best thing I could recommend would be to just turn on the heating, in the summer times, when you want to activate the hot water or perhaps change the schedule during that period of time so it suits you for heating the hot water. 

[UanaC]

Hi there! Just checking in with you. Did you see the message from above?

[FuManchu]

Thanks for the follow up. Had missed it.

Silly question but can you set it to just turn on?

It all seems to be temperature based. If room is under X temperature turn on for a minimum of an hour, I feel like I'll just have to accept setting a schedule like this to ensure hot water in the morning during summer. Feels a bit daft that the scheduler is restricted to 1 hour or when temperature is meet minimum.

[LarisaL]

Hello there, @FuManchu! The easiest way to control hot water and the heating at the same time is to create a schedule for hot water and for heating. If you want to use only the hot water at some point in time, you can create a schedule only for it. Thanks, Larisa.

[OannaCG]

Hi there! Just checking in, did you manage to see the message above?

[FuManchu]

I did but it does not resolve my issue.

The wiring is only set up for heat as there is no segregation on my system boiler. I.E when it's on its heats both water and radiators. The wiring is also just set for the heat so I already knew I would need to use the heat schedule which is what I am trying to avoid, it Nest allowed 30 minute schedules it would be a non issue but I do not need a full 1 hour during the summer, it's a waste of fuel.

Anyway I think I'm either resigned to getting the system rewired so call for water just triggers the same call as call for heat as you can set water to 30 mins or deal with my system being on for an hour every morning via the standard heat schedule.

[AlexD]

Thank you for all the information. Currently that is the time frame for heating schedule, as usually heating a location takes longer than heating up a water tank it was set to that timeframe to prevent short cycling. 

Should there be any updates to the functionality we'll make sure to let everyone know on our official channels. We're always looking for ways to improve our products and services.

The only other thing I could suggest is to manually turn the temperature up or down to activate and deactivate the heating to run it for hot water. Though it would be probably best to modify the system so you can wire up the hot water side for control.

I will go ahead and close this thread for now. If anything else comes up or you have any updates to share, make sure to open up a new one and let us know. Have a great day ahead!