Preparation in case of boiler / smart thermostat failure?

[floob]

Before I had my new combi boiler and Tado installed I had an older system with a separate water tank. If that old boiler ever had issues I could simply use the immersion heater in the water tank and still have hot water.

Now that my new combi boiler has Tado connected, as far as I can see I cant even force the boiler back to manual mode if I needed to (it seems to need to be 'commissioned' by a plumber). If Tado/Boiler comms breakdown it looks like it could be a major issue. If relevant its a Vitodens 100-W B1KF connected with Opentherm protocol to Tado.


So my question is really, in order to pre-empt an issue with the boiler being connected to Tado and no heating requests getting sent to the SRVs or hot water firing, what is my best bet?

I'm thinking I should buy a spare Tado wireless receiver and bridge, and the moment the boiler/tado stop talking to each other, call the plumber and give them the spare unit, or get them to set it/commission to manual operation so it will actually provide hot water/heating?

 

[ianmcd]

If that old boiler ever had issues I could simply use the condenser heater in the water tank and still have hot water.

What is a condenser heater in a HW Tank ?

 

[vulcancontinental]

Do you mean TRV not SRV?

If you're thinking about getting a spare Tado in readiness and you then need someone to commission it, instead, and cheaper, why not just link out the switched connection in the boiler control box - a bit of wire, cost, nothing.

OpenTherm defaults to running if communication is broken, ring Tado and ask what their protocol does.

Alternatively, get an electric shower fitted so you can keep clean and an electric fan heater to carry from room to room to stay warm until the boiler is fixed.

 

[floob]

What is a condenser heater in a HW Tank ?

Argh - sorry, I meant immersion heater.

 

[floob]

Do you mean TRV not SRV?

If you're thinking about getting a spare Tado in readiness and you then need someone to commission it, instead, and cheaper, why not just link out the switched connection in the boiler control box - a bit of wire, cost, nothing.

OpenTherm defaults to running if communication is broken, ring Tado and ask what their protocol does.

Alternatively, get an electric shower fitted so you can keep clean and an electric fan heater to carry from room to room to stay warm until the boiler is fixed.

When I say SRV I mean these (https://www.tado.com/gb-en/smart-radiator-thermostat-add-on) when they turn on because the paired wireless temp sensor tells them to, the boiler currently fires up.

I've got no idea how to do this "why not just link out the switched connection in the boiler control box - a bit of wire, cost, nothing" but I presume a plumber would?
Would that mean it ignore the Tado and can revert to a manual mode?

Thats a good idea about the electric showers - any obvious disadvantages compared to the ones that need the gas combi? Not wildly different in cost to run or change in pressure output? I might do that.

The boiler is hooked up to Tado using Opentherm, so are you saying normally that would just switch to always on if comms broke?
I'll see what Tado say to that query. Thanks for all the pointers.

 

[CBW]

So my question is really, in order to pre-empt an issue with the boiler being connected to Tado and no heating requests getting sent to the SRVs or hot water firing, what is my best bet?

I'm thinking I should buy a spare Tado wireless receiver and bridge

Heed @vulcancontinental ’s advice, or cross the bridge when you come to it. Have you no faith in the boiler or Tado? Say the pcb fails, what then? 2nd Tado rendered useless. Save your money, and maybe a little each month to pay for an engineer if or when required.

 

[floob]

Heed @vulcancontinental ’s advice, or cross the bridge when you come to it. Have you no faith in the boiler or Tado? Say the pcb fails, what then? 2nd Tado rendered useless. Save your money, and maybe a little each month to pay for an engineer if or when required.

I think its the fact that I've jumped from a 30 year old boiler and immersion heater where a few kicks one way or the other would always get something working, whereas now if Tado anticipates that in 45 mins the outside temp is going to drop by 1 degree it'll pre-empt it and reheat the one specific room for 9.6mins to hit the target temp - it feels all a bit out of my hands now. Based on that, I'm just concerned given I don't seem to be able (as an end user) just flip it to a manual mode and ignore the oepntherm commands in case the Tado unit develops a fault.
I just want to be in a position where if I suddenly have cold water and no heating, that I'm able to get up and running as quickly as possible, particularly if the failure relates to the Tado side of things (so many moving parts with receiver, bridge, SRVs, wireless temp sensor).

That said, these modern boilers and smart thermostat systems are all very reliable, right?

 

[Razor900]

The boiler is hooked up to Tado using Opentherm, so are you saying normally that would just switch to always on if comms broke?
I'll see what Tado say to that query. Thanks for all the pointers.

it's in the OT protocol that if there's zero resistance between the terminals, (ie there's a link in), the system will revert to on off operation.

If you're really that worried get someone to wire a lightswitch in parallel across the OT terminals.

Then you just turn it on in the event of a failure

 

[martygturner]

Go into the menu and select constant operation and set the timer if you want...its built in...the boiler will operate at the temp you set...and ignore all the other inputs.

 

[floob]

Go into the menu and select constant operation and set the timer if you want...its built in...the boiler will operate at the temp you set...and ignore all the other inputs.

Thats really what I want to be able to do, and am struggling with it - so I shouldn't need to change the operating mode to be able to do that?

When I scroll through the P options here:

The only ones that appear as I scroll through are P2, P5, P6, P7, P8, P9, P10, P11

I cant access P4 which looks to be the one I want?

Maybe this is the issue?

 

[martygturner]

Yes you will need to change the mode, switch it to mode 1 then p4 becomes active. But you will need to set up 15 or 16 again when you flip back...there is a software tool for windows to do that. You could also wire in a room thermostat for back up, and set the boiler to mode 13. In a loss of comms I would rather be warm and spend a bit of time resetting the rads up rather than fault finding in the cold.

If I were you I would get the tool down and make yourself familiar with it, its not complex. Its just a bridge between the rad valves and the boiler, just tells each other that they exist.

 

[floob]

@martygturner Thats what I'd like to do, but I cant see how to do it without re-commissioning


From the User Manual

From the Installation Manual (I dont really fancy mucking about with the gas shut-off valve or the 'trap')

In terms of flipping back to OpenTherm, I see their app details here (https://www.viessmann.co.uk/residential/smart-home/viessmann-apps/vicare) but I cant see a dedicated windows application?

 

[floob]

Ok, so Viessmann have said:

"The change from Opentherm to manual has to be done from the Commissioning screen, option C7:14 to C7:1 then go to last setting in list until END shows then confirm with OK. The Commissioning Screen is where the Installer set up the Boiler functions, this is in the Installation and Service Manual that the Contractor had on receipt of the Boiler, there are other settings in there that, if changed by mistake, could put the boiler into a fault state, so in theory, this should only be done by a competent Person, i.e the Installer or a Heating Contractor."

So if I wanted the boiler to change to manual, I need a plumber. Even if I wanted to do it myself there are no instructions in the user manual of how to change commissioning mode. I've looked at the installer manual above and I guess I could try that, but I'll need to start using the software tool and start using the gas valve - I dont fancy that.


Tado have said, to avoid that:

"So the only thing you need to do is turn off the power and then open the tado receiver front cover. Connect both +/- wires together by for example connecting them in one slot (example: connecting both +/- wires in connection + so that they are both together). This will make your heating come on permanently and you will then need to turn the boiler off when the heating is no longer needed."


So it sounds like if the Tado receiver breaks, I should do that. But to be honest I dont want to play about with wires, so either way I think I'll just call the plumber asap to sort it. It still sounds like to me, if I wanted Tado up and running after a hardware failure I should have a spare receiver handy.

 

[August.33]

Hi,

How is your boiler and Tado so far?

 

[floob]

Hi,

How is your boiler and Tado so far?

Really good thanks. Its been a very reliable combination.
I was worried about the lack of manual access to easily override once OpenThermwas configured, but its not been an issue. Between the Tado and ViCare app, they do a good job.
I had a bit of an issue when internet access went down, but the manual overrides worked without a problem, it was just I couldnt use the app to control or update anything.
I've bought a spare Tado unit in case the one attached to the boiler breaks, but hopefully it wont come to that. I've also got the details of a local Viessmann accredited engineer, so hopefully any issues will be quickly resolved.

Its certainly been a vast improvement in terms of efficiency and cost saving compared to my previous setup.