Another Hive Install Question

[NTA]

Hi,

I have searched the forum but not found an answer that matches my question.

I have a dual channel Hive and want to wire to my Vaillant 831 Plus combi.

Reading the manual and also the forum. I believe i need to so the following can someone please tell me if its correct.

3 core flex cable

Remove Vaillant thermostat from boiler BUS terminals
Boiler N > Hive N
Boiler L > Hive L

Boiler RT > Hive 4

Many thanks

 

[mrStat]

1. Remove and make safe the BUS wires from Boiler
2. Remove the RT 24v link in Boiler
3. L Boiler to L on Hive
4. N Boiler to N on Hive
5. 230v RT Boiler to 4 on Hive

Note: You should be getting a suitably qualified/registered person to check the boiler over on completion as the front panel forms a secondary combustion seal on this appliance.

 

[NTA]

Thanks very much.. Why does the 24v link need to be removed btw?

 

[muggles]

If the 24v link was left in, the boiler would just run continuously.

As MrStat has suggested, you shouldn't have removed the cover of your boiler unless you're Gas Safe Registered and competent to carry out the required 26.9 checks to bring the boiler back into operation. You should call a Gas Safe Registered Engineer to carry out these checks before the boiler is used again

 

[NTA]

Thanks

 

[Taylortwocities]

As MrStat has suggested, you shouldn't have removed the cover of your boiler unless you're Gas Safe Registered and competent to carry out the required 26.9 checks to bring the boiler back into operation. You should call a Gas Safe Registered Engineer to carry out these checks before the boiler is used again

Is that really the case? Just to make the electrical connections?

 

[bernardgreen]

Is that really the case? Just to make the electrical connections?

It does seem that way. Even for boilers which have no air ( or gas ) tight base plate for the front panel to seal to..

 

[Taylortwocities]

Blimey. The base of mine has a load of holes in it. Those coppery pipe thingies go through them.

 

[mrStat]

I am not sure what is so confusing about all of this... Warning: Rant about to start...

This type of boiler has a pre-mix burner; the main "combustion" chamber (The silver tumble dryer drum) is under positive pressure... Gas and air are mixed at the head of the burner and pushed into the chamber where it is then ignited under pressure. If this combustion seal leaks; then a mix of burnt or unburnt gas will be expelled into the outer casing.

The front panel does not have any obvious seal; but it is designed to create a "negative" pressure zone around the heat exchanger; thus causing any dodgy gases (Burnt/unburnt) to get drawn back through the combustion process and allow the mix to fall out of ratio and fail to rectify; thus causing the appliance to shut down.

Most boilers like this will have a sticker on them (Usually on a Vaillant a great big yellow one on the inlet duct) or a big bold note in the manual stating that the appliance must not be operated with the front panel removed for a long duration, some state that operation with the front panel removed is actually strictly forbidden - This is because the front panel is intrinsically linked to the safety of the appliance.

I am sorry that people find this really hard to understand - But all because you cannot see a rubber seal; it does not mean that there is no seal... On this model you will notice the red rubber grommets around the cables; the pipes are mechanically sealed to the rib of the case... They have not done this for fun - It is part of the combustion process failsafe... As such; the work is restricted to competent persons. I know that 3 wires is pretty easy; I also know case checks are pretty easy - But most modern boilers the logic of "if it needs a tool to do it; you need a registration to do it"... I have already seen 1 electrical company running around installing Nest thermostats on Vaillant boilers be served a "prohibition notice" by Gas Safe and that kind of backs up the fact that this is "registered works".


Sorry - rant over.

 

[bernardgreen]

"if it needs a tool to do it; you need a registration to do it"

My rant is that registration does not mean the person is competent.

 

[mrStat]

My rant is that registration does not mean the person is competent.

I’m not going to hijack the OP and I get what you mean. But I have to say it as I see it. I don’t come on here to wave the big “I know more than you do” flag - I just want people to be aware that they need to be cautious when opening these things up. If an ACS centre signs someone off and a GasSafe Inspector is happy for someone to work; then it doesn’t matter whether I think they are a complete spanner or not... They’ve jumped the hurdles and should they fall, that’s their doing. If someone DIYs and something happens because of the advice I gave; at least I can sleep at night because I told them the correct process. I can pour the water into the glass, but I cannot make someone drink it.

It concerns me when people say there is no seal or purpose to the shiny white decorative panel. I just want people to be aware that it is there for a reason; if it needs a tool to open it, it’s likely it was not designed for the user to open. That is why manufacturers have “user instructions” and “installer instructions” - you will never see user instructions showing you how to wire up or letting you know how to pop the case off to bell out a thermistor.

 

[NTA]

1. Remove and make safe the BUS wires from Boiler
2. Remove the RT 24v link in Boiler
3. L Boiler to L on Hive
4. N Boiler to N on Hive
5. 230v RT Boiler to 4 on Hive

Note: You should be getting a suitably qualified/registered person to check the boiler over on completion as the front panel forms a secondary combustion seal on this appliance.

So I did all of this and all seems good. Heating comes on when set from the thermostat and the phone. One thing I have noticed is that if I stop the heating, on the boiler, the radiator symbol for heating goes off as expected but the boiler still makes noise. Left it over 5 mins and it's still making noise but the heating symbol is off and I definitely removed the 24v link. If i turn the hot water on and off the boiler then stops the noise. Will have to get BG to come have a look.

 

[mrStat]

Heating signal goes off, Hive Receiver led should flash for a bit, then make a click noise, then rad symbol on front of boiler should flash for a bit as the boiler “runs on” to clear its heat.

The run on period will depend on the heat left in the heat exchanger.

 

[NTA]

Thanks will leave for longer then 5 mins and see if it goes off.

 

[mrStat]

@NTA - does the rad symbol on the front of the boiler start to flash when the demand is removed?