# Removing Steam Knob From Delonghi Bar 14



## CoffeeMac

Hello all you experts out there. I am a new member of your wonderful group and need some help.

As a starter machine I just bought a Delonghi Bar 14 s/h. It seems great to me and makes good coffee but I have a yen to PID it and need to get at the innards to see if it would be feasible. I am being thwarted by the steam button which does not want to be pulled. The steam button needs to be removed to get the top cover off, hopefully exposing the boiler, etc. I am reluctant to apply too much force for fear of breaking the thing but suspect it should be able to be shifted.

Has anyone been successful in pulling the steam button off and how?


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## CoffeeMac

It's off! Just needed a firm 2-handed pull when hot after brewing. Knob is splined to match splined shaft of steam valve in brass. Next step is to get the top panel off to explore potential thermocouple sites and heater/thermostat terminals for PID and SSR. Thinking of sourcing these from far east - seem very cheap.


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## BanishInstant

Interesting. Hope it goes well.


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## lookseehear

If it's the same machine as the Delonghi Treviso (which I think it is!) then it shouldn't be that difficult to get the top cover off. There are four plastic screw covers on the corners but pick those out with a knife or similar then there are screws underneath (I think they were hex screws but a small flat-head did it).

I believe the steam knob does need to come off but it's just a friction fit so just give it a good pull straight up and it should come off (just noticed you did actually get this off in the end).

I would say before you pid it, think long and hard about it. The boiler is tiny and doesn't have a very big heating element, so even if you can control the temperature accurately, I don't think the element would 'keep up' as it were. Also, they're very cheaply made (ours has developed a leaky boiler after only 6 months) so I'm not sure it's really worth the effort/cost. It is entirely up to you though, it'd be interesting to see as I doubt many people have bothered to pid these before.

Edit: I've just remembered that the newer ones of these seem to come with a pressurised pf (it has a black plastic bit at the bottom) so if yours is one of those I would seriously think about at least trying to source a non-pressurised version, as putting a pid on a machine with a pressurised pf would be like adding NOS to an electric wheelchair!


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## liquidmonkey2000

I have my doubts that trying to PID a machine like this will offer any noticeable benefits. The cheapest PID kits I can find are £32.52 +£22.52 P&P which make this mod more expensive than the machine you are putting it on. Perhaps you can source them cheaper from the far east as you say.

When I started out on the guitar I would try out all sorts of mad experimental modifications to guitars and equipment. Though most of them ultimately proved to be useless, I learned a lot by trying them out. Sometimes you just have to try things, if only to come round to realisation that the orthodox approach is there for a reason. Sometimes conventional wisdom needs to be challenged and proved wrong.

So although I have my doubts about the success of this project I hope you will prove me wrong. Whatever happens I am very interested to hear how you get on.


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## Osh

liquidmonkey2000 said:


> When I started out on the guitar I would try out all sorts of mad experimental modifications to guitars and equipment. Though most of them ultimately proved to be useless, I learned a lot by trying them out.


You just reminded me of when I was 14 and broke and couldn't afford an electric guitar yet. Tried to build my own pick-ups!! You can imagine the rest. Enough said.


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## CoffeeMac

Thanks for your comments and support. It's as much experimentation as hoping for huge benefits. The PF is unpressurised. Have the bits on order from HK, total cost incl postage 27 pounds.

Existing wiring is well put together, better than I expected for a cheap machine. Overall very impressed with it's build quality.

Looks like the present thermostats will need to be disconnected and controll for both espresso and stem turned over to the thermocouple/PID.

In the meantimew will be trying to measure existing temperature changes in the thermal cycle, pull drop, thermostat lag etc. Should help with PID setup when it arrives.


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## CoffeeMac

Just finished measuring the temperature cycling in the Delonghi Bar 14. I attached a thermocouple to the boiler top surface with a home made clip mounted on the thermostat/thermal fuse carrier stud. Objective was to measure the top and bottom temps for the espresso function i.e.static boiler temps before pulling a shot, and the temp drop while pulling a shot. The temperature were measured using an RS digital thermometer.

Results over 5 cycles of heating and natural cooling gave averages as:

Temp at TS open (heating off) - 222F

Max temp reached (from coil thermal mass) - 231F

Temp at TS closed (heating on) - 208F

The boiler continues to heat up by a further 9F after the coil is switched off because of the coil thermal mass.

This gives a maximum swing in the boiler of 231-208 = 23 F made up of 14F TS lag + 9F overswing. This seems quite low compared with some (maybe apocrophyl) accounts of >40F swing for other machines.

The temp drop in pulling a shot was 17F, occuring during the TS lag space.

The challenge for PID will be to hold the static temperature at say 230F within a degree or two and to reduce the temp drop during shot pulling.


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## liquidmonkey2000

Very interesting and detailed results. When do you get your PID?


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## CoffeeMac

Should be getting PID and SSR in about 10 days. I'll be adding photographs of the project once I can work out how to!


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## Glenn

Have just emailed details

The Go Advanced tab will give you more options


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## attix

Nice thread!







I just bought the same machine and started to thinking about an electronic thermostat (with PIC microcontroller + I2C temperature sensor + a triac for the boiler control.)

I'm now researching for the exact boiler capacity, flow rate and the exact heater wattage to design a proper PID controller...

Anyway, what is the end? How it is work? Are you satisfied with the result?


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