Jump to content
IGNORED

Steam Boiler Overpressure


Recommended Posts

Hi,

Sorry if this is covered in another post but twice in the last 6 months I’ve had the over pressure valve on my Alex Mark 2 activate (almost giving me a heart attack in the process).

This has happened since I replaced the valve using one from Bella Barista (who told me which one to get so it should be the right one).

The machine is 10 years old and aside from this, in very good working order.

The steam boiler had been on for several hours and I hadn’t checked the pressure just before it exploded (but assume it was well above normal).

just before it happened, I was about to make a flat white so put on the steam for a little bit to dry it out. It was quite wet. However, the water level sensor is pushed right down (and not long ago cleaned and descaled) and I hadn’t pulled any steam that day so not surprised it was wet.

Since the first time it happened, I turned down the steam temp but now it’s happened again, I’m worried there is a fault I’ve not thought of.

If anyone has any experience of this problem and the solution that would be great.

Mark 

Link to comment
Share on other sites

@Izzoalex Mark, can you remove the machine top cover, take a photo and upload it here...with the mark 2 there were some versions with a pressurestat and the very late MK2s I think moved to electronic temperature control of the service boiler. A photo of the inside will tell me which one you have.

Sticks and Stones, sours…or rancid (horrible). Quakers hide until roasted, pick em out and flick them in the bin. Life is too short for bad coffee

 

 

Link to comment
Share on other sites

Hi DavecUK,

 

Thanks for this.

 

I should probably mention that prior to installing the new over pressure valve, I had a hissing leak just near where it attaches to. I repaired this with JB weld as shown. Not sure if it would be of relevance to this problem but I mention it just in case.

I’ve also replaced the PID this year.

Mark

326DA8FF-BB90-41B0-B222-1CCA357DEBDB.jpeg

7C051F40-187A-45EF-AF09-A60127C9F79A.jpeg

Link to comment
Share on other sites

@Izzoalex Yours is electronic control, the JB weld is around the bade of the "Safety Valve". Ideally, take that JB weld off and use lead free silver solder on it...it's a far better repair. Clean it up well and use a good flux.

Check the temp sensor wires are not loose in the PID or corroded, if not, remove and check the temperature sensor probe casing for scale....You don't say what water you are using, but I'm going to guess it's hard and you don't descale, or at least descale aggressively....where do you live, what water do you use in the machine?

If it's not scale, then replace the temperature sensor.

P.S If you clean the machine up, you can see if it's leaking anywhere else, before you insulate the boilers.

 

Edited by DavecUK

Sticks and Stones, sours…or rancid (horrible). Quakers hide until roasted, pick em out and flick them in the bin. Life is too short for bad coffee

 

 

Link to comment
Share on other sites

Thanks again v much.

Thanks for the tip re the weld. I did look into solder at the time but I didn’t really feel I confidently knew how to do it and the tools needed. I’ve not done it before and couldn’t find anything very useful online (eg videos). It is something I’d like to do though, I don’t imagine the JB weld will last long term.

thanks for that re the temp sensor, I don’t think I’ve ever looked at it or cleaned it up.

I’ll also double check the wires.

I live in Essex but use bottled water (presently ashbeck English from Tesco). I used to use a Brita filter and descale every month or so in the first few years of owning the machine but now rarely bother descaling given all the caution against it on sites like this.

 

 

Link to comment
Share on other sites

I was going to say "stop using sea water in your espresso machine" (the green patina is created by Cl- on copper). At least so I read, could be wrong. Anyway, if it is right Ashbeck leaking all over the boiler would make sense. How often do you flush (refresh) the water in the service boiler? If the answer is "never, I don't want to waste the bottled water" then as Dave says it could be very much scaled up and the water will be highly concentrated in there with chloride, sodium, sulphate, nitrate, and potassium concentrating while calcium, magnesium and bicarboante reach a balance where scaling will occur if it's heated and any excess will be deposited in the boiler.

Link to comment
Share on other sites

7 hours ago, Izzoalex said:

 

----------- but now rarely bother descaling given all the caution against it on sites like this.

 

I live in SW Scotland and use bottled water ( Ashbeck English from Tesco) but will revert to tap water following data from Scottish Water...Very soft water - no scale at all in kettle after 5 years usage

can somebody supply the link to the ''descaling caution''  discussions...?   thanks

..regards...................john...:coffee:

Link to comment
Share on other sites

Hi

Thanks for all the further comments. In fairness, I don’t replace the water in that boiler as often as I probably should then. Hopefully then it might just be a scale issue.

Re my caution comment, I should probably clarify I meant ‘over descaling’ with references I’ve seen over the years to damaging the machine.

Thanks again 

Mark 

 

  • Thanks 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...