On 23/10/2018 14:59, wrote:
Update:

Nothing much to report on the DHW. It still fires and starts to get
warm, then the flame goes out and it runs cold. The heat exchanger
is hot to touch. This will repeat a few times.

What's new is that the CH now will throw a F.75 error unless the
pressure is really high. For example, over 2.0 bar (which then
increases of course as the heat flows). But resetting the error and
upping the pressure makes the CH run fine.

Manuelle he says: "Water pressure sensor and/or pump defective, air in
the heating installation, insufficient water in the product; connect
external expansion vessel to the return"

Could it be that the new pressure gauge I fitted is kaput? What are
the chances of that?

Possibly... you should have two pressure gauges though - there is the
digital one on the front panel display, and then the little mechanical
one you can see with the front cover of the boiler removed (to the right
of the pump - you may need to fold the electronics box forward to see it).


--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
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On 26/10/2018 13:17, wrote:
On Tuesday, October 23, 2018 at 4:26:11 PM UTC+1, John Rumm wrote:

Could it be that the new pressure gauge I fitted is kaput? What
are the chances of that?

Possibly... you should have two pressure gauges though - there is
the digital one on the front panel display, and then the little
mechanical one you can see with the front cover of the boiler
removed (to the right of the pump - you may need to fold the
electronics box forward to see it).


Hi John,

Yes, there are two pressure gauges. The digital one runs from the
pressure sensor that I replaced and the analogue one is quite
literally stuck on the same reading whether there is water in the CH
or it is drained down. I am guessing that there is some much in the
little copper pipe that runs to it.

I might try draining down again and testing the pressure in the
expansion vessel. Not sure if that will help, but worth a shot.

You don't need to drain down completely for that - just let out enough
water to release the pressure on the system. Just allow for a bit of
under reading since you will have the weight of the head of water
pushing on the pressure vessel even if there is no actual pressure in
the system as such.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/