No hot water with new installed Alpha etec plus 33kw boiler unless CH is put on for at least 15mins!

[steph-p]

Hi there

We’ve recently installed a new Alpha Etec Plus 33kw Combi boiler. However, we won’t get hot water unless central heating is put on for at least 15mins. If we put CH on and run the tap straight away, we will get an error “E43” on the boiler.

We have had the engineer from Alpha out to inspect the boiler and found no faulty with it.

The installer has been out and noted it’s to do with the pipe size and that there’s too many bends in the pipe run before it gets to the boiler, and advised that we change the pipe from 22mm to 28mm. (But this will mean we have to lift the flooring, floor boards etc and trace the pipe run!)

Does anyone have the same issue, or could anyone think of any other possibly cause other than pipe work sizes?

Thanks

 

[ianmcd]

very confusing post and you need to be more clear, E43 is an ignition fail and nothing to do with HW, do you mean that the installer is saying that the gas supply pipe is undersized ? If so they should have up graded it during installation, if You had alpha out under warranty and the gas pipe was undersized they would have issued you with paperwork telling you of this

 

[steph-p]

Sorry for confusion.

So installer is saying pipe work is undersize, they did not flag this up before installing the new boiler. We are not getting hot water unless we put CH on. He said everything is fine and “it must be the gas pipe work being undersized as there are too many bends in the pipe run before getting to the boiler”. We just wanted to find out apart from undersized pipework, if there would be another possible cause.

Could you please clarify what you meant by “if you had alpha out under warranty as gas pipe was undersized they would have issued you with paperwork telling you of this?”

Thanks

 

[Gasguru]

The gas regulations require a maximum drop in gas pressure from the meter outlet test point ( have a look on the RHS meter connection) to the boiler inlet (there should be another test point there) of 1mbar. This is to guarantee gas appliances function correctly and remain safe.

When the boiler was commissioned this pressure drop should have been checked with the boiler is running flat out.
Some installers ignore the regs since upgrading the gas run can be very disruptive and expensive.

When the Alpha eng. came out if he suspected and tested the pressure drop and found it to be excessive he should have issued you with an advice note.
What sort of distance is the boiler from the gas meter? Modern boilers will often function on lower gas inlet pressures but the fact remains it contravenes the regs.

 

[ServiceNumpty]

Got to ask, how did the installer commission the boiler properly if it kept going to E43 on hot water. What does the benchmark commissioning page say.Something doesn't ,make sense here. Particular the visit by the Alpha Tech and no paperwork.

 

[steph-p]

@Gasguru

Alpha eng never issued any paperwork after the inspection. I’ll call them to come out and have a look again regarding pressure drop etc. The gas meter is a room in the underground car park, and travelling circa 15m before popping through the concrete floor up to ground level, and it terminates outside our flat.

I queried the installer as the gas pipework and gas supply was fine before we changed the boiler, and his explanation was that older boilers (the one that was removed was about 10yrs old) is either on or off, and modern boilers require more demand for gas supplies to power up the boiler, hence we only noticed the undersized pipework after the new alpha boiler has been installed.


@MikeCip
E43 error only comes up if we turn on hot water before putting CH on (we HAVE TO put CH on before getting any sort of hot water).

 

[Gasguru]

Alpha have every right to charge you if the problems are down to installer error.
What was the previous boiler? Was it a combi?
Your installer is talking rubbish.

The mystery remains why you only get the E43 error when running the hot water. Modern boilers fire up at a specific "power" regardless of whether the demand is for heating or hot water.

Post a few pics of the boiler and pipework underneath.

 

[steph-p]

The previous was a Combi Boiler too.

Here’s some photos of the boiler and pipework underneath.

One of my colleague had mentioned that it might be an issue with the diverter valve so I’ve mentioned to the installer, and he said it can’t be that and “it MUST be the pipework size!”

 

[ianmcd]

I very much doubt that it has anything to do with the size of the Gas pipe, as already said if it was the Alpha engineer would have issued you with a notice and would have told you about it, the boiler uses exactly the same amount of gas when lighting for CH or HW

 

[steph-p]

@ianmcd

Noted, I’ll be in touch with Alpha again and get them to send an engineer to come back out to carry out another inspection.

 

[ianmcd]

with the CH off do you get a tap symbol on the boiler display as soon as you open a hot tap ?

 

[steph-p]

Yes, the tap symbol comes up

I tired to upload a video but file size is too large

 

[ianmcd]

i would ask Alpha to come back out, even if the gas supply was inadequate the boiler would still light whether the heating was being used or not

 

[steph-p]

thanks. I’ll arrange with alpha tomorrow

 

[steph-p]

So I've just phoned Alpha, and the notes from the engineer who came out for the inspection noted the gas pressure drops to 8 millibar when the hot water is switched on.

They said it might be that there is blockage in the pipework, or the pipework is undersized?

What I don't understand is I was able to get hot water from my old combi boiler before. Is the gas supply/ pressure a lot more erroneous with new boilers?