# PL62T Low steam pressure



## Jbcook (Aug 29, 2021)

Hi all. First post, hope it's okay to dive in with a question!

I recently bought a used PL62T (the Hx with the PID). Makes lovely espresso so far but I'm having a problem with steaming.

The steam pressure guage shows 0.7bar at all times, dropping to 0.5 or less during steaming which makes steaming pretty slow/difficult.

The manual says the pressure should be at 1.1bar or so.

I've tried flushing, running lots of steam through. No change.

I've tried turning the machine on with no flush/shots and it's still 0.7 bar after 40 mins of warming.

Any ideas on how I could resolve this issue?

Thanks!


----------



## DavecUK (Aug 6, 2013)

It's programmed into the Gicar box firmware, inside the machine. Is it still the original box? Or has the temperature probe been changed?

It's also worth tracking the temperature probe wires to the box and checking everything is OK, take a photo or two if you want.


----------



## MediumRoastSteam (Jul 7, 2015)

@Jbcook - welcome to the forum.

what temperature is the PID set to?


----------



## Jbcook (Aug 29, 2021)

Thanks both. It's in the original box as far as I know. The previous owner adjusted brew pressure to 9bar but didn't do anything else.

He says it was working (steaming) fine on the day I got it from him, so it's possible a wire has come loose in transit.

At 115 on the PID the steam pressure is 0.3.

At 121 on PID, the steam pressure is 0.5ish

At 126 on the PID, the steam pressure is 1bar.


----------



## DavecUK (Aug 6, 2013)

@Jbcook *Discount what I said* *earlier*...I thought you had the early Mara model, I just looked it up and see you have an external PID. Check to see an offset is not programmed into the PID by going into the advanced settings. It could be that the PID is displaying a different temperature to the actual temperature.

Yours is this machine, right?


----------



## Jbcook (Aug 29, 2021)

Okay, will do. How do I access the advanced PID settings?


----------



## MediumRoastSteam (Jul 7, 2015)

@Jbcook - so, the drop of pressure when steaming is absolutely normal. From memory, it would drop 0.2 or 0.3 bar as soon as you open the steam tap. However, it should then keep roughly at it during steaming or drop, gradually, very little. Don't worry about that.

Post below shows a table with the correlation between steam temperature and pressure.

https://www.home-barista.com/espresso-machines/is-there-temperature-vs-boiler-pressure-table-t3308.html

115C: 0.7 bar, 126C: 1.4 bar

either your probe is misreading the temperatures or you pressure gauge is faulty and reading with an offset of approx. -0.4 bar. This is unlikely given the symptoms described, i.e.: "steam is pretty slow/difficult".

Best to open the machine up and check all the wires and check for water and steam leaks.

if none, then maybe remove the probe and give it a clean.

*And, just to be sure:*

- are you sure you didn't change any of the PID advanced parameters, such as the offset value? (I'm unsure if your machine actually has one)

although, for any positive offset value, the temperature displayed will be LESS than the temperature inside the boiler, which negates the experience from the OP.


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> Okay, will do. How do I access the advanced PID settings?


 Dave to confirm. If there are such settings, they can be accessed by:

Turn machine off;
hold both + and - buttons on the pid;
whilst holding them, turn machine on and keep holding them until you see F.01 or something like that.

Press the minus to jump through the parameters. You want to find the E setting. Press the plus button to change

however, if you never saw the advanced settings, it's unlikely your problem is there - unless your friend changed things before selling it to you, which is unlikely too I'd assume.


----------



## Jbcook (Aug 29, 2021)

Okay. Accessed and changed the offset to test. Steam pressure does indeed rise as expected but then the PID flashes which I believe means it's too hot for coffee?


----------



## MediumRoastSteam (Jul 7, 2015)

@Jbcook - maybe. What setting did you change, what was the value and what did you change it to?


----------



## Jbcook (Aug 29, 2021)

I changed f.04

Changed from 0 to 7 which bought the steam pressure to 1.1/1.2

Changed it back down to 0 again now as I wasn't sure I liked the PID flashing!


----------



## Jbcook (Aug 29, 2021)

An update:

I realised that the f.05 Value was set to 122 and that the PID would flash when the temp was above that.

Set f.05 to 127 and f.04 to 7 and all is good! 1.1bar of steam pressure roughly


----------



## MediumRoastSteam (Jul 7, 2015)

@Jbcook - do you know what F.04 does? I would not change anything unless you know what you are doing!


----------



## Jbcook (Aug 29, 2021)

As far as I understand it, it's the offset for steam temp?


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> As far as I understand it, it's the offset for steam temp?


 That's fine, if that's what you say. I'm assuming you checked the manual or something.

so, he offset is now set to 7. So, if the temperature is set to 127, this means that the water temperature is 134, which would equate to approx. 2 bar, but your gauge is displaying 1.1 bar.

The thing is, there should *not* be an offset. It should be zero. You want the display tortellini you the exact temperature inside the machine.

Do this test:

Change the offset back to zero. Let the machine cool down.

when it warms up, listen in very closely. At some point, you hear the machine hissing and a valve closing, and the hisses stop. That's the vacuum breaker doing it's job. When you look at the PID, providing it actually displays the actual temperature, what's that number? It should be between 98 and 102, which is when pressure starts to build and, you'll notice the pressure building up and the gauge to move, providing its working properly. This will tell us whether it's the temperature sensor or the pressure gauge at fault.

so, please let us know what temperature the display is showing when the valve closes.


----------



## Jbcook (Aug 29, 2021)

Thanks.

I actually did this test this morning. Steam hissed until 100 and promptly stopped hissing. This was prior to making any PID adjustments


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> Thanks.
> 
> I actually did this test this morning. Steam hissed until 100 and promptly stopped hissing. This was prior to making any PID adjustments


 that's interesting. This implies the temperature readings are correct. If you were to repeat the test with your current settings, then the value you'd read would be 107, which is wrong.

Now, given all the information above, something seems to be amiss. It doesn't make any sense.

If your machine is now operating at 134C, this is 2 bar pressure. Way over the top, way above the limits for your machine.

something is not adding up. The gauge should not be showing 1.1 bar for a temperature of 134C.

Question: how do you know that setting F.04 is the offset?


----------



## Jbcook (Aug 29, 2021)

MediumRoastSteam said:


> Question: how do you know that setting F.04 is the offset?


 https://www.kaffee-netz.de/threads/lelit-pl41-plus-t-dampf.118868/

Different model, but relates to the PID settings. Seems this model is set to "8" for f.04 whereas mine was set to 0. Different model, so of course that may be expected.

I just re ran the warming up test with my new PID values, and this time it stopped hissing at 93 degrees, 7 degrees lower than prior. Re reading the URL above shows that f.04 works in the negative, so "7" is actually "-7degrees"

Machine again warmed from cold to 121 on the PID, steam pressure showing 1.1bar.

In my earlier efforts to solve this problem, I did do a PID reset, perhaps this set the f.04 value back to 0 when it should have been 7/8.


----------



## MediumRoastSteam (Jul 7, 2015)

Interesting. The vacuum operates by physics. When pressure starts building up, around 100C, it is pushed in shut, and seals it, allowing the rest of the pressure to build.

setting the offset means your machine is operating at a very high temp, as proven by the vacuum breaker shutting when PID displays shows 93C when offset is 7. You could have kept the offset to 0, and set the temp to 134C.

ps: I meant to say 93 not 107 on the post above. The way offset works is:

display temp = actual temp LESS offset.


----------



## MediumRoastSteam (Jul 7, 2015)

There's a reason why you need offset on the PL41. It's because, by the time the temperature reaches the group, it would have lost heat. The offset value corrects this. So, on a single boiler SBDU or dual boiler, this makes sense: the temperature in the boiler is 103C, the offset is set to 10, the display shows 93C.

* Your machine is an Heat Exchanger machine (HX). I'll repeat, an offset value makes absolutely no sense. *

If I were you, I'd remove the probe and check it over for limescale or have it checked over by a qualified technician.


----------



## Jbcook (Aug 29, 2021)

Okay, great. Thanks for the explanation. I've reset everything on the PID now and steam is back to 0.7bar.

As a temporary workaround I can increase the PID to 126(max) which boosts the steam up enough to froth milk.

I'll try and get into the machine in the week.

Thanks for all your help so far.


----------



## MediumRoastSteam (Jul 7, 2015)

For you to have an idea&#8230;

when I had my profitec 700, the steam boiler was set to 126C. The pressure showed approx. 1.3 (maybe 1.4 bar) on the gauge. It was a while ago.

I now have a Lelit Elizabeth, set to 140C, and the pressure shows just above 2 bar pressure (the gauge is not very precise ).


----------



## MediumRoastSteam (Jul 7, 2015)

Also, with a pin, make sure you clean the holes on the steam tip. You'd be surprised on the difference it makes! The steam tip can be unscrewed from the wand.

also, do you know what water was used on the machine? Could it be that you have scale build up and that has clogged up the inlet of the gauge or something, thus the pressure readings are off?


----------



## Jbcook (Aug 29, 2021)

Morning,

Not sure exactly on the makeup of the water, but the seller said it was south Wales tap water filtered with a Brita filter. Cleaned/backflushed weekly.

I'll check the tip too, but fwiw it steamed great when the pressure was >1bar and not so great at its current of 0.7bar.


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> I'll check the tip too, but fwiw it steamed great when the pressure was >1bar and not so great at its current of 0.7bar.


 Good you are having great results. But you seem to be missing the point: your pressure gauge is not correlating to the temperature of your boiler. If your boiler temp probe is reporting correctly - well, you tested it, by confirming the vacuum breaker shuts off at 100C, then the pressure your gauge is reporting is incorrect. At your set temperature of 134C, it should be reading around 2bar.

Your cooling flush must be insanely long.

something is not right with your machine. What you are reporting does add up in normal circumstances.


----------



## Jbcook (Aug 29, 2021)

I'm not necessarily missing the point (I think) I'm aware something is wrong with the machine, I just need the time to take it apart to see what it is.

Why must my cooling flush be insanely long? How long should it be!?


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> I'm not necessarily missing the point (I think) I'm aware something is wrong with the machine, I just need the time to take it apart to see what it is.
> 
> Why must my cooling flush be insanely long? How long should it be!?


 Ah! Ok. I thought you accepted that increasing temperature was just fine. 👍 - good stuff. Worthwhile having a closer look for sure.

re: cooling flushes. The reason I ask is the temperature has increased significantly, thus you now potentially need to flush considerably longer to get to the point where flashing boiling water stops in order to pull a shot.


----------



## Jbcook (Aug 29, 2021)

MediumRoastSteam said:


> Ah! Ok. I thought you accepted that increasing temperature was just fine. 👍 - good stuff. Worthwhile having a closer look for sure.
> 
> re: cooling flushes. The reason I ask is the temperature has increased significantly, thus you now potentially need to flush considerably longer to get to the point where flashing boiling water stops in order to pull a shot.


 Okay, cool.

Well the PID is now set to 121 with no offset again, so the water shouldn't be too bad.

Something I did notice this morning which may or may not be relevant was that when opening the brewing lever to the pre-infusion position, water came out, but no steam.

I crudely measured the water coming out of the hot water tap and it was 90 degrees, which is what would be expected I guess.


----------



## DavecUK (Aug 6, 2013)

MediumRoastSteam said:


> Ah! Ok. I thought you accepted that increasing temperature was just fine. 👍 - good stuff. Worthwhile having a closer look for sure.
> 
> re: cooling flushes. The reason I ask is the temperature has increased significantly, thus you now potentially need to flush considerably longer to get to the point where flashing boiling water stops in order to pull a shot.


 Agrees, interestingly this actually gives a different problem users don't actually think about....If you have to flush large amounts of water it really chills down the HX unit and fils it with a large volume of cooler water. This can often result in the actual shot becoming too cool. This is because the heat transfer rates from the boiler to the HX don't really rise in a totally linear fashion.


----------



## MediumRoastSteam (Jul 7, 2015)

MediumRoastSteam said:


> For you to have an idea&#8230;
> 
> when I had my profitec 700, the steam boiler was set to 126C. The pressure showed approx. 1.3 (maybe 1.4 bar) on the gauge. It was a while ago.
> 
> I now have a Lelit Elizabeth, set to 140C, and the pressure shows just above 2 bar pressure (the gauge is not very precise ).


 @Jbcook - actually found a photo from back in the day!

you can actually see it: 126C, 1.4bar.


----------



## Jbcook (Aug 29, 2021)

Ah good find!

Thanks for all your help so far. I've contacted Lelit who are sending the videos/photos onto their technicians so we'll see what comes of it. I'll be sure to update here though.


----------



## Jbcook (Aug 29, 2021)

Morning,

Lelit have got back to me and have asked that I set the f.04 value to 5.

The settings on my PID must have been incorrectly set, somehow.

They've asked me to run the machine like that for as few days and let them know how I get on.

What do you think of that?


----------



## DavecUK (Aug 6, 2013)

I can't remember what F.04 is for, it might be setting for 2 boilers...just can't remember.


----------



## Jbcook (Aug 29, 2021)

DavecUK said:


> I can't remember what F.04 is for, it might be setting for 2 boilers...just can't remember.


 Its the offset for temperature, but as @MediumRoastSteam said, it doesn't really make sense in a hx machine.

I've asked them if this is how the machine should have been set or if they're using it as a workaround (and giving me a very high boiler temp in the process)


----------



## DavecUK (Aug 6, 2013)

@Jbcook Perhaps Lelit have a reason for programming an offset to compensate for somthing?


----------



## Jbcook (Aug 29, 2021)

@DavecUK That's what I'm assuming, I've asked for clarity. As before, I've adjusted it to 5 as advised and the steam pressure is now 1.1bar


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> @DavecUK That's what I'm assuming, I've asked for clarity. As before, I've adjusted it to 5 as advised and the steam pressure is now 1.1bar


 Interesting. Does the vacuum breaker now shut when the machine displays 95C?


----------



## Jbcook (Aug 29, 2021)

I've not had chance to start the machine from cold to check, but I'd assume it will. Can't see how it would do anything else!


----------



## Jbcook (Aug 29, 2021)

As suspected, Lelit have got back to me and confirmed that changing the f.04 value to 5 is not as per the factory default settings. They've said to try it and leave it unchanged if it works.

Surely, though, as discussed above this means my boiler temp is actually 5 degrees higher than the PID is reading. So if I'm brewing at 121 I'll actually be brewing at 126 (I know the group temp is different to boiler temp).

I'm tempted to leave it at 0 and bump the temp up to 126 on the PID when I need steam, rather than brewing everything at 5 degrees hotter than the PID reads.

Still tempted to open it up and check the temp probe, as it must be that or the pressure guage which is wrong.


----------



## MediumRoastSteam (Jul 7, 2015)

@Jbcook - It's not the brewing temperature as such. That's not how an HX work. There's no harm in having that temperature, because its an HX machine. 126C is just fine, but it will require a longer flush. Without a thermometer on the group, you'll never know what's going on.



Jbcook said:


> As suspected, Lelit have got back to me and confirmed that changing the f.04 value to 5 is not as per the factory default settings. They've said to try it and leave it unchanged if it works.


 So they said you should leave it as 0? That makes sense. But then, it confirms that there's a problem somewhere (as discussed on the previous posts). Offset or no offset you still have the problem.


----------



## Jbcook (Aug 29, 2021)

MediumRoastSteam said:


> So they said you should leave it as 0


 Sorry, no, I wasn't clear. They've said set it to 5 and if that works, leave it at 5.

Okay, forgive my ignorance around Hx machines, must have misunderstood. Without having a group thermometer could you roughly tell me what sort of flush time you'd recommend? And is that just for the first shot in a batch of say 3, or would you flush for every shot?

Yes, if setting it to 5 isn't the factory default, there must be an issue somewhere!


----------



## MediumRoastSteam (Jul 7, 2015)

Jbcook said:


> Sorry, no, I wasn't clear. They've said set it to 5 and if that works, leave it at 5.
> 
> Okay, forgive my ignorance around Hx machines, must have misunderstood. Without having a group thermometer could you roughly tell me what sort of flush time you'd recommend? And is that just for the first shot in a batch of say 3, or would you flush for every shot?
> 
> Yes, if setting it to 5 isn't the factory default, there must be an issue somewhere!


 Yeah, defo something going on there.

I can't tell how much you need to flush. Each machine have their own patterns. You flush for the first shot in a batch, and then keep pulling shots afterwards. That's why they are great in a busy cafe! For home... Not quite as much 🙂

There are videos which give you techniques and signs to look for when flushing HX. Worthwhile googling up.


----------

