# La Pav Pro boiler problems.



## Batian (Oct 23, 2017)

Long story short, over a couple of days my La Pav Pro began playing up. Then yesterday it stopped heating.

I PM'd jimbojohn55 and sought advice. It has now got complicated, not least because the innards in my machine do not seem the same as the pics and expanded diagrams at The Espresso Shop website, nor indeed pics on this forum.

Refer to pic below.

So following Jimbo's advice, using a multi meter I found that I had power to terminal labelled 1 from the illuminated switch. There was no power from terminals 2,3 and 4 between them and earth or neutral.

Changing the multi meter to measure ohms, I got no resistance 1,3 and 4 and earth or neutral. I got no resistance between any combination of 1,3 and 4.

I did get resistance between 2 and 3. (2 being normally connected to the pressure stat )

Testing the pressure stat with mains on and switch illuminated gave no power at 6 and 7. It did show resistance between (power off) 6 and 7 and between them and neutral. But not between them and earth.


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## El carajillo (Mar 16, 2013)

Is that a resetable limit switch at the centre ?

Have you tried disconnecting the main heating element terminals and checking for continuity / resistance and also check each terminal to case (earth)

Also try disconnecting terminals to limit stat and try rotating the adjuster screw (note original position

Check each section of cable end to end for continuity / resistance.


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## DavecUK (Aug 6, 2013)

What resistance value in Ohms did you get between 2 and 3 (not a great photo, but they look like the heating element terminals, because of what looks like the white insulation sheath coming up the wires).

The pressurestat should be normally closed, so will pass electricity until the boiler water and pressure is high enough to click it open circuit, so between the red wire (that presumably goes on terminal 2 and the green wire coming off the top of the Microswitch, electricity should pass with pretty much no resistance at all. If it's open circuit, then the pressurestat may need replacing (or unsticking, if you are cheap).

It could be a faulty switch (doubtful from what you say), see if the switch is OK, by checking the poles with a resistance meter, Pavoni should not be plugged into mains of course.

P.S. It's possible that the fusible link has gone....from the photo it likes like that thing between 1 and 4 and I guess is there so it can melt if things get too hot. I can't see a resettable stat...but as I say that's not the best quality photo....so you need a new phone as well


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## Batian (Oct 23, 2017)

Thanks for your input El carajillo.

I did try moving the stat adjuster 1/2 a turn in both directions.

The small thing in the centre is a screw with what appears to be a castellated washer. This retains the bar that are part of the terminals labelled 1 and 4

Your other suggestions were all carried out (I think!!) as in my opening post.

.


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## El carajillo (Mar 16, 2013)

As Dave said that looks like a fusible link in the centre, you can see more clearly on 2nd photo.

The lower element terminal (in photo) looks corroded. It also looks as if it has leaked around the nut / pipe.

Did you get continuity across the fusible link ?


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## jimbojohn55 (Jan 15, 2016)

that is a thermal fuse in the centre if its blown its not resettable, but can be replaced with the later resettable type - you could try bypassing it to see if you get the element to work - but be carefull and unplug while you work on it.

if your testing the element resistance with ohms disconnect the wires from the terminals first

This is a reasonable guide if a little detailed http://coffee.gurus.net/pavoni/diagnostics/


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## Batian (Oct 23, 2017)

Yep, the phone is a year old (this month) Samsung S8.... Cant afford anything better at the moment! 









Re Davec Q and resistance between 2 and 3.

With the multimeter set to Ohms and 2K, initial contact produces .483 and then fades down to a steady .054

The mains switch is a few weeks old and supplied by The Coffee Espresso Shop. The old switch worked but did not light up. I will check the switches poles tomorrow and report back.

Any thoughts on why mine does not resemble the expanded diagrams on The Coffee Espresso Shop?

El carajillo.

re leaks around the nut/pipe

To me it looks as if there has been a sealant squigged under the nut when it was fitted???? It certainly has a varnish like appearance.

Corroded lower element?

I refer to the pic and terminals 1 and 4, the latter being the lower element you refer to(??) There is no sign of any corrosion as is, but I have not looked under the porcelain insulators.

However, the bar ( fuse?) that 1 and 4 terminals are mounted on has the lightest of rusting. Pic 2 is a good representation.

There was no resistance between 1 and 4.

More info. Testing the resistance between the centre screw (that holds the bar with 1 and 4 terminals) and earth produces a reading of .192 rapidly declining to .001 Terminals 1 and 4 to earth is 0.


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## Batian (Oct 23, 2017)

Update post site outage...

I tested the resistance on the switches terminals as follows.

The multimeter was set to 2K.

The numbers below relate to the picture and are as they appear moulded on the switch.

1 >5 = 0

1 >4 = 0

4>5 = .541 decreasing rapidly to 001

1>2 = 765 decreasing rapidly 001

2>4 =0

2>5 =0









Following instructions from jimbojohn55 (thank you) I bypassed thr fuse and found that the element is working. A modern replacement has been ordered. My thoughts are (at the moment) that the pressure stst is OK as the pressure gauge never went above 0.9, but I will run a test once the new fuse is fitted.

Thanks to all for the input, and I will report back.


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## jimbojohn55 (Jan 15, 2016)

when in edit mode look at the box under the txt editing box there is a button that says manage attachments that lets you delete attached images etc

Glad the pressurestat is ok 0.8 -0.9 should be spot on - you might find that you need a new pressurestat pipe £12 if the entry hole on the new element is in a different position the old ones can fracture if you bend them too much, either way get a 50p reel of ptfe tape for the thread on the pipe when you connect it to the new element, glad its back on the mend


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## Batian (Oct 23, 2017)

The new fuse arrived this morning. Pics of what arrived.

Guess what, the hole in the bracket is smaller than the existing screwbolt! I suppose I shouldn't be to surprised.

So do I just drill it out a tad, or am I missing something?

I assume the bracket is squeezzed over the metal part of the fuse barrel? The bracket does have a shoulder, and I assume it is placed as shown in pic 2?

Thank you everyone!


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## AndyDClements (Aug 29, 2016)

In the last image you're nearly there, the legs prongs of the bracket go the other side of the flange/ lip on the sensor. That way, when screwed to the machine the clip holds the flat disc to touch the base of the boiler. If you have any thermal conducting compound (as used on computing heatsinks etc) that would be best as it ensures a speedy transfer in heat energy so any over-temp problem would cause the sensor to trip more swiftly.


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## Batian (Oct 23, 2017)

Thanks. Gotcha. I was thinking metal bracket to metal of fuse rather than the plastic barrel. I will se if I can scrounge some thermal conducting compound....

Just the screwbolt/bracket hole problem now....


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