New boiler nightmare

[Miseryguts]

I have emailed him explaining that we are getting someone in to power flush the system, which will hopefully satisfy the boiler warranty conditions and this is our immediate priority. Hopefully the Gas Safe inspection won't find anything too problematic and then he can come back and complete the installation. We can sort out the liabilities afterwards.

The gas pipework looks like about 8 meters long from the meter, all in 22mm copper with about 4 elbows. Does that sound okay for a 24kw boiler?

He hasn't been paid anything as yet, but he did reply to my email today reminding us that he is out of pocket for materials - should we be paying towards his outlay while this is going on?

 

[johnny2007]

What material???
He's got the boiler, he just needs a few bits of copper which he should have in his van

 

[gas112]

800 left in will knacker the pump very quickly

 

[Miseryguts]

Well..... it's reassuring to hear that the plumber has offered to reduce his bill by £500 to cover the cost of a powerflush. He has also offered to pay for and install a wireless thermostat, instead of a new cable between the hot water cylinder and the programmer, which will enable hot water and heating to be controlled independently. So I guess he wants to do the right thing and now I'm feeling a bit bad about getting Gas Safe involved.

Two more questions please, if any of you learned folk are happy to advise:-

1) Finding someone to powerflush at short notice seems 10x trickier than finding a plumber. I was surprised at some quotes being well over £1k, while a national firm advertising on Google was the only one under £500. Is this a job that can be done well or badly, despite having the correct equipment and is there anything I need to be wary of?

2) You can see there is a 2 port valve next to the hot water cylinder in the attached photo. There is another near the boiler, which I thought indicated an S plan layout. However, the wiring from the water cylinder valve only goes to the immersion heater, so the programmer cannot prevent water being heated when the boiler is running. Apparently, the wireless Drayton thermostat set up proposed by the Plumber costs around £300. Is this the best way to get this to work properly, or is there a simpler/cheaper option?

 

[polesapart]

Picture shows a cylinder thermostat.

 

[Miseryguts]

...which is wired to the immersion heater along with the 2 port valve. There is no cable to the wiring centre near the boiler, hence the question.

 

[polesapart]

I think you'll find that the second white cable exiting the junction box goes to the main wiring centre.

 

[Hugh Jaleak]

...which is wired to the immersion heater along with the 2 port valve.

It cant be, a Motorised Valve will only handle a minimal current, and are not capable of switching an Immersion.

The Motorised Valve should be operated by the Cylinder Stat, to open to allow flow through and fire the boiler when the temperature in the cylinder drops below the set parameter.

 

[Miseryguts]

The plumber explained that in normal use the thermostat is doing nothing at all and the the primary circuit only stops running when the boiler stat is satisfied. Perhaps it works when the immersion heater is on, but we need it to work when the boiler is on.

 

[polesapart]

How many cores does the second white wire have?

Any less rhan five you need a wireless setup, or a new cable.

 

[Miseryguts]

Thank you. That is what the plumber said - needs a 5 core cable to the wiring centre. So is wireless the best way to go and if so, does that cost around £300?

 

[muggles]

Yes, power flushing is very much a job that can be done well or badly.

 

[Miseryguts]

I think you'll find that the second white cable exiting the junction box goes to the main wiring centre.

No, just to a fused outlet on the wall.

 

[polesapart]

Yes, but where's the wires feeding that box connected to?

It looks to me that what you have is a pre-existing botched attempt at a S-plan which your installer can now only correct with wireless or new wiring.

The immersion switch is the lower of the two wall boxes and not directly related to the boiler controls.

 

[fixitflav]

The plumber explained that in normal use the thermostat is doing nothing at all and the the primary circuit only stops running when the boiler stat is satisfied. Perhaps it works when the immersion heater is on, but we need it to work when the boiler is on.

An option is to run the boiler and pump from the cylinder stat. The drawback is that when CH is called the cylinder could get hotter than the stat setting. But it does that with the current set-up, and since the cylinder stat does nothing, the cylinder isn't heated (by gas) except when CH is called, which it isn't in warm weather.
The system could be converted tp a S, W, Y-plan by adding a 2-port valve or changing to a 3-port.