2 heating zones plus hot water - guide unclear to me!

david9374652

The guide included with the app doesn’t appear to clearly replicate my system.

I have 3 heating zones in the house plus and unvented cylinder for hot water.

Downstairs - Danfoss TP9000 which is a thermostat / programmer for both downstairs heating and hot water. It’s wired.

Upstairs - Danfoss thermostat / programmer for the upstairs heating only.

Loft - EPH wireless thermostat / programmer. Received located next to water tank in upstairs of house.

Danfoss wiring box, located next to water tank.

I plan to leave the loft EPH wireless system in place as the room is seldomly used and introducing wiring may be problematic (or not?).

Downstairs - replace TP9000 with wireless v3+ starter kit inc water.

Upstairs - replace TP4000 with additional smart thermostat.

I’m not clear whether the wires I should start to label are behind the downstairs room controller (doubt it) or the wiring box. The instructions seem to consider a simple installation of one zone plus water. So the mass of wires in the wiring box are confusing me to say the least.

Here’s some photos of the wiring for a start:

Any help appreciated!

wateroakley

@david9374652 The wireless receiver needs mains power, from the same fused circuit as the boiler/controls. You could put the wireless receiver in the same cupboard as the wiring box.
You’ll need to figure out the connections in the wiring box that go to the TP9000 and connect these to the receiver. Looking at the piccie, best guess … 13 is N, 14 & 15 are L. You’ll have to figure out which of 9 10 11 & 12 you need to rewire and connect to for CH1 and HW. If in doubt consult a professional.

policywonk

IIRC the tado full starter kit includes an Internet bridge, a wireless receiver/ extension box. The wireless receiver, extension box is crucial. It enables you to replace all the timers and furthermore allow you to install smart TRVs on every rad in the house. These then allow you to set the temp by time of day for each rad, and separately switch on the boiler to replenish the hot water tank via time set in the app.
There may be a room stat supplied in the kit. But when you do implement it, you don't have just one timer. The app enables each point, each rad with the smart trv installed to be a separate zone, the hot water has its own app based timer and it all hangs together. I found the spend on smart rad stats the most significant source of savings in one year.
Hope this makes sense. You still have to buy the smart TRVs, but they really do save money.

policywonk

I assume you have one pump. All the the zone valves do is release the pumped CH into one of three heating loops. If two open, two loops are served and I presume your pump has enough savvy to provide a constant differential pressure. This is important because let's assume you have 15 rads in total on the three loops. In practice each rad, when it opens, needs a consistent pressure to serve correctly.
By adding individual smart trv heads one removes the need for each loop to be separately turned on, because if only one rad needs heat it will open its valve and the pump will drive the water through. Now it doesn't matter whether one or ten rads are demanding heat all those needing heat will keep the boiler going until all rads shut off. When they do, they drop their indiviual requests. When there are none needing heat the extension kit shuts down the boiler on their behalf.
So if you select to install smart trvs, you need to consider removing some of those zone valves. Only you and your plumber and decide on that. It is a matter of balancing lengths that the pump had to handle. Also need to think about whether the pump can deliver a genuine differential pressure head. Many pumps don't. Those that do save money, lots.
I work inside a facility that has 27 rooms being heated on three floors, with one zone valve for the ufh on the ground floor, one for hot water, but all the rads have smart rad stats. You still have to balance the rads, have a good pump, but the smart rad stats made it all work without any drama.

policywonk

Study the Grudfos smart pumps range. The right models make a huge difference, in that they automate the pressure they produce as the rads open and close, but one needs careful time and thought to set them up right. The one we have uses an app to help set up pressure from the farthest to the closest.
It does take time, thought but for us it was worth every penny we spent. Had lots of drama when we took over the property because what was there was both simple and implemented well before smart controllers, smart pumps and smart trvs were in existence. This does involve slow thinking.

wateroakley

@david9374652 Your upstairs and downstairs choices for Tado seem right to me. A wireless starter kit and add-on wired thermostat.
Replace the TP9000 with the wireless receiver for CH1 and HW. Replace the TP4000 with the wired thermostat for CH2. You should be able to add TRVs and optionally wireless room stats (if needed). You probably don’t need to touch the wiring centre.

david9374652

Thanks for your reply. I did wonder if that was a solution, but because the TP9000 is a programmable thermostat it’s in the hallway at the bottom of the stairs. Not a great location for the wireless receiver.

Does the wireless receiver need separate power? I’ve read something about wiring it to a 3 pin plug.

Is there a way to place the received somewhere less prominent, for example in the airing cupboard where the wiring box is?

Thank you!

david9374652

Thanks so much. That makes sense.

david9374652

One final question!  I mentioned the wireless EPH controller for the loft (heat). If I install wireless for heat and water downstairs, then I’d need to make the loft wired. 

It’s a relatively easy job to run cables to where they’d need to be.

To replace the wireless EPH receiver, I think I’d be simply swapping the receiver for the wired stat, although extending the wires in the process. The tado app doesn’t seem to cater for this arrangement. 

What will the connections to the wired tado thermostat look like compared with the EPH receiver. 

Many thanks

wateroakley

I’ve not come across the EPH controller before. That said, you have Live and ON, I ‘d be minded that the Tado wired stat should do the job to replace your EPH and don’t forget to safely terminate the other wires.

david9374652

what about the N wire? Looking at some diagrams I’d interpreted it as follows from EPH to Tado:

ON to N/O

L to COM

N to P1

And those loose 2 wires don’t connect to anything at the other end.

What do you think? Thanks again!

wateroakley

Sounds good to terminate N on P1. One of the loose wires is Green/Yellow, indicating an Earth wire? Always recommend to safely terminate unused wires, even if they don't appear to be connected to anything.

policywonk

I don't understand the q about the loft. Do you have dedicated rads in the loft? If so either replace the flow valves with tado wireless stats, or replace the EPH stat with a wireless tado room stat.

Have I missed something in the complexity here?

david9374652

Hi - as I need to control hot water then there will be a wireless zone downstairs for heating and hot water and I can only have 1 wireless zone.

The loft conversion was after the house was built and has its own heating zone with 2 rads.

I do want the loft to be heated and controlled independently to the upstairs or downstairs of the house. Hadn’t considered wireless stats. Would this replace the rad TRVs or something else?

policywonk

@david9374652. Unfortunately the web version of this forum and the app both seem to have presented the Qs and As in the wrong order. So to ensure you are clear:

1. The supply to the boiler should be fed by the junction box you photographed above. It also supplies power to the Tado Wireless Receiver- and Tado should have given you advice on the pin wiring in that junction box. If not and if you are still worried, come back here.
2. If you elect to keep the EPH controller, then @wateroakley has given you enough to go on. He's also given you a logical explanation of how to finish the connections. However if you are still lost come back here.
3. Would still recommend that you swap the TRVs heads (a Tado Smart TRV head simply replaces most TRV heads), for a Tado one. It removes the need for the additional stuff. They seem to be discounted right now, if one searches carefully. They simplify the running of our home and when we replaced all TRV heads with a Tado one, we recoverd the cost of the smart TRVs within 1 year.
4. There are two types of V3+ Tado TRV heads being sold, one is more expensive and displays the temperature it is reading with symbols an inch high and I prefer that to the one with simple leds that one has to study with spectacles! We tend to use the ones with the large display in bedrooms and living spaces, and the one with the tiny display in bathrooms.

Good luck.

david9374652

Thanks to all who have replied. The more info I read the more questions I have!

To go back to my setup, I have 3 heating zones with individual pipework with each connecting to a flow valve. So only when one of the current 3 wired or wireless thermostats call for heat do these valves open (at least I think that’s what happens!).

I have the wireless starter kit and will wire the receiver to control the downstairs zone (along with hot water for the cylinder).

I am planning to replace the wired thermostat / timer upstairs with a wired tado.

If I opt to leave the wireless EPH in place for the loft, could I then use smart tado TRVs for the 2 rads in the loft? Would I make these a zone in their own right and just leave the EPH to ON at max temp? Then I would set schedule for the TRVs via the app?

And if I were to install tado TRVs more generally, how do these work with existing room sensors? I’m getting confused over what controls what in a TRV setup!

david9374652

Thanks again for the detailed input. I’ve managed the first basic installation with the only problems being configuration of zone controllers and getting the wireless receiver to be configured for water. I bit of resetting and trial and error sorted that out. I’ve left the loft as is for now. I’ll have a think about smart trvs but as you say will need a plumber to make that work as efficiently as possible.