Boiler not firing up sometimes

[JohnWB]

I put this problem to the forum 3 weeks age and everyone said I should get the installer back.

I did that and he could not find a problem.

I also had British gas out twice (I have a yearly maintenance contract with them) and the first man changed the motor on the Honeywell 3 port valve - result no difference. The second man changed the complete 3 port valve after checking that all the voltages were ok and again no change.

Does anyone have any ideas where the problem could be. I have updated what the fault appears to be


I have astrange problem (to me). Sometimes the new Worcester 18RI does not fire up whenI would expect it to, for example.

I sometimes get up in the morning and the heating has not come on. If I turn off the hot water using the Hive controller then the boiler fires up and the radiator start to get warm


Does this sound ok or could there be a problem.

 

[ShaunCorbs]

sounds like something with your hive setup maybe

 

[Gasmk1]

it sounds like a it could be problem with the wiring have they wired the cylinder stat correctly or is the cylinder stat faulty

 

[SimonG]

Sounds like a wiring issue.

 

[JohnWB]

I'll have a check but it was fine before the new boiler went in, maybe they moved a wire or something.

Thanks for your help again, I will report back with the results (one day soon hopefully)

 

[JohnWB]

I've been doing some checks of the wiring in the Honeywell junction box and I have attached a photo of the present layout

I looked at an old photo taken before the hive was fitted and the only thing that changed when the hive was fitted, was a link where the room stat was.

The only thing I can see that has changed on the new photo since the new boiler was fitted is the new brown live wire to the boiler and the grey wire from the boiler connected by chocolate block to the brown wire to the pump. (the switched live to the boiler is now black instead of brown previously)

Should there have been any other changes or links cut etc.

SEE BELOW FOR POST WITH PHOTO

 

[JohnWB]

I've been doing some checks of the wiring in the Honeywell junction box and I have attached a photo of the present layout

I looked at an old photo taken before the hive was fitted and the only thing that changed when the hive was fitted, was a link where the room stat was.

The only thing I can see that has changed on the new photo since the new boiler was fitted is the new brown live wire to the boiler and the grey wire from the boiler connected by chocolate block to the brown wire to the pump. (the switched live to the boiler is now black instead of brown previously)

Should there have been any other changes or links cut etc.

 

[JohnWB]

I have been doing some more checking and reading various Honeywell documents.

Should the grey wire from the boiler that has been put into the chocolate block go into the boiler P/L terminal in the photo above, and the brown wire it was connected to, go back into the pump L terminal above. Also, should link 6 be cut.

 

[Old Account]

I would not cut link 6

 

[JohnWB]

I would not cut link 6

I am going by the Honeywell diagram I have attached which says to do so in Note 4, now I am no expert so you could be correct

 

[Gasmk1]

I would ask them to rewire it in a normal wiring centre as it could be that one of the links that was cut originally should be whole again either that or just get them to start from scratch

 

[Old Account]

I am going by the Honeywell diagram I have attached which says to do so in Note 4, now I am no expert so you could be correct
View attachment 29040

But only if your boiler requires pump overrun, it basically means that the pump runs for a short period after the heating is turned off... to take away any hot water from boiling and damaging your heat exchanger ...

 

[JohnWB]

I would ask them to rewire it in a normal wiring centre as it could be that one of the links that was cut originally should be whole again either that or just get them to start from scratch

According to the Honeywell info the correct links were cut and the only one different could be the link 6 that I mentioned

 

[Old Account]

According to the Honeywell info the correct links were cut and the only one different could be the link 6 that I mentioned

But only if your boiler requires pump overrun, it basically means that the pump runs for a short period after the heating is turned off... to take away any hot water from boiling and damaging your heat exchange.

 

[Old Account]

Who connected boiler - p/l with pump - L?

 

[JohnWB]

But only if your boiler requires pump overrun, it basically means that the pump runs for a short period after the heating is turned off... to take away any hot water from boiling and damaging your heat exchange.

The boiler is a Worcester 18Ri which does require pump overrun

 

[Old Account]

According to the Honeywell instructions, boilers which require pump overrun the links 4,5&6 should be cut and the wires ( boiler = p/l ) should be connected into the terminal as well as the ( pump = l ) should be connected to the pump terminal.

 

[JohnWB]

The boiler installer

 

[Old Account]

The boiler is a Worcester 18Ri which does require pump overrun

If it requires then link 6 should be cut and wires should be connected into the terminals as shown on your previous Honeywell instructions.

 

[JohnWB]

According to the Honeywell instructions, boilers which require pump overrun the links 4,5&6 should be cut and the wires ( boiler = p/l ) should be connected into the terminal as well as the ( pump = l ) should be connected to the pump terminal.

That is what I said in post 8, I was checking to make sure i was correct

 

[Old Account]

The pump, cylinder stat and the diverter valve are supplied pre-wired that's the dot line in your diagram.

 

[JohnWB]

The crossover between different peoples posts causes some confusiion doesn't it

 

[Old Account]

That is what I said in post 8, I was checking to make sure i was correct

Yes, you did. I didn't know what boiler you had just read it now.

 

[Old Account]

That is what I said in post 8, I was checking to make sure i was correct

Yes, you did. I didn't know what boiler you had just read it now.

 

[quality]

All you need is a decent heating engineer as the system you have got is not complicated but may be causing confusion to folk who have looked at it since its been modified

 

[Gasmk1]

he has a hive for controlling the system so something is wrong either with the wiring or the hive programming

 

[Old Account]

But, if you do not feel confident enough then I would suggest get a professional electrician out.

 

[JohnWB]

But, if you do not feel confident enough then I would suggest get a professional electrician out.

I am happy enough do do it but I always like to check with the experts

 

[mfgs]

You don't need to cut link 6. The pump live is wired direct to the boiler as the PCB in the boiler controls the overrun on that boiler.
It will be a control issue. You just need someone to spend a little time going over the wiring to check the controls.

 

[Old Account]

You don't need to cut link 6. The pump live is wired direct to the boiler as the PCB in the boiler controls the overrun on that boiler.
It will be a control issue. You just need someone to spend a little time going over the wiring to check the controls.

Is that the correct way to not use the terminals and connect the pump l to boiler p/l ? I am just wondering if you cannot use the terminals and cut link 6

 

[Old Account]

You don't need to cut link 6. The pump live is wired direct to the boiler as the PCB in the boiler controls the overrun on that boiler.
It will be a control issue. You just need someone to spend a little time going over the wiring to check the controls.

Is that the correct way to not use the terminals and connect the pump l to boiler p/l ? I am just wondering if you cannot use the terminals and cut link 6

 

[JohnWB]

Well I connected the wires as we said and cut the link 6 and it all seems to work ok including the pump overrun.

Now I have to see if that has cured the origional problem

 

[mfgs]

It will work that way, but the boiler is now not installed to manufacturer's instructions so you could risk voiding the warranty. The pump should be wired directly to the boiler.

 

[JohnWB]

So does that mean that if you have a Honeywell Junction Box you cannot use it to connect the pump to the boiler.

Does that apply to using any junction box or does the pump have to be wired directly to the boiler

 

[JohnWB]

How does the Honeywell JB link 6 affect how the overrun work