Profitec Pro 700 - Losing temperature, not heating back up

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
MrBaggins

#1: Post by MrBaggins »

Hello,

First time poster after going through numerous helpful posts. The issue I'm having has really confused me. For background a close friend of mine passed me his machine as he's moving back to Europe, he had mentioned it recently had stopped being able to reach the right temp - he's tried to troubleshoot it a bit but had hit of a bit of a dead end himself. Since then, I've been tinkering a bit (hopefully not doing too much damage!)

Essentially there are a couple issues together:

1. On occasion where the machine is able to reach temp. The temperature dramatically drops from 94°c to something close to 75°c after pulling a shot. I saw this is quite common, but unusually the issue I'm having is after pulling a shot, the temperature fails to return back to 94°C.
2. Furthermore, once this happens, the temp of the steam boiler starts to drop. If I run the steam wand, it just loses pressure and keep dropping the temp.
3. On occasion when starting the machine, the brew boiler might reach temp but then as the steam boiler starts to heat it seems to max out/stop heating and eventually begin to lose temp again.

I've tried a few things:
1. At first when the machine wouldn't get to temp, I turned it on with the lever open, it pulled a bit of water and then once I closed it the machine was able to reach full temp. Then after pulling one shot, it dropped and didn't return.
2. I check the highline safeties at the top and they seem to not be tripping - well they don't click when I press them.
3. I reset the PID to factory settings.
4. I tried to drain the machine, letting it heat up, turning it off and then tilting it 45° with the lever up, then turning the tap on for the steam boiler to drain.

Of note - the brew boiler didn't seem to drain much water, not even a cup worth! While the steam boiler emptied more than a pint as expected. After doing this I thought I'd managed to get it back working - managed to pull a shot, it still dropped temp by was able to reheat. Then I turned the lever on to rinse the grounds off and then the temp seemed to stick around 80°C. Then I tried to backflush with the blind portafilter mainly just to clean it before packing it in for the night. While back flushing I heard some sort of screeching around 4-7s in. Couldn't really locate where the sound came from, but I decided to just stop at that point.

Apologies, this is a bit of an information dump and really all over the place. At this stage I'm wondering if it's a valve issue or possibly a relay switch issue.

Appreciate any help!

Nunas
Supporter ♡

#2: Post by Nunas »

I don't have a magic fix for your problem, but I'm familiar with the machine, as it is a first cousin to my Synchronika. Here's what I think. The brew circuit and the steam circuit on that machine are totally separate. The only common element is the PID. That's my first and only guess until we have some more information or discussion. As for the screaming sound, is your machine fitted with a flow control valve atop the e61? An e61 with an FCD set wide open will often scream a few seconds into a pull, at least mine does. BTW, it will also scream without an FCD if the jet (gicleur) is missing. Concerning boiler capacity, the brew boiler on these machines is smallish, about two large coffee cups of water in total.

JRising

#3: Post by JRising »

If you run the pump against the blind basket for several seconds, where does the pump gauge settle? If it's over 11 bar, your pump pressure may be opening your expansion valve, making it scream with that high flow. Easy fix by adjusting your pump pressure down a little, you don't want it that high, anyway. More is not better in pump pressure.

Nunas
Supporter ♡

#4: Post by Nunas » replying to JRising »

Good suggestion. To add a little about how these things go awry, some of the 700/Synchronikas appear to have two places to adjust the brew pressure. Many folks wrongly think that it's the internal brass valve with the big straight slot screw, accessible from the top of the machine. It's a natural error, as the valve closely resembles the OPV on a machine fitted with a vibe pump. That's actually a system safety valve, which should be set about 1.5 bar above the pump pressure. The proper pump adjustment is on the bottom of the machine, as the pump is an inbuilt bypass for pressure adjustment. If by any chance you messed with the safety valve, I believe you can restore it to the proper setting easily. First, you increase the pump pressure way up. Then you adjust the safety valve to open at about 1.5 bar over your intended pump pressure, then you return the pump bypass to your intended pump pressure. So, please advise if you happened to mess with this valve. If so, then perhaps John can jump back in and confirm that my suggested resetting procedure is correct.

MrBaggins (original poster)

#5: Post by MrBaggins (original poster) »

Thanks you both for the replies. I don't think it has a flow control valve on the top of the e61. It is one of the older machines with the two nuts. See picture.

In terms of pressure I personally haven't adjusted it at all. Can't be sure about my friend although I don't think he did either. Generally the pressure on the brew gauge wasn't jumping out at me, staying around the green marked area. But I'll double check again with a blind basket to confirm with you guys.


MrBaggins (original poster)

#6: Post by MrBaggins (original poster) »

So quick update. Pressure wise. When pulling a shot into the blind basket, the pressure maxes out top end of the green range (10Bar I think). The screeching noise occurs at about 9bars for a second where the pressure meter also slightly falters. It's as if the water is having to force past something that is slightly stuck. I'm fairly sure it's coming from the lever mechanism as the handle also gives a little shake once the machine is able to push past to 9 bars.

However, I did two things this morning and since the machine seems to have responded well. For now at least.

Firstly, I opened it up and noticed one of the control boxes (the one near the water tank) was wonky. I readjusted it and made sure to just press in all the wire connections which looked like they had been pulled out a bit. Not totally convinced that was the issue though.

Secondly, I turned on the machine with the brew lever on for some time, approx 5/10 minutes. The group head was giving off steam but not trickling water. Then I closed it and let the steam boiler get up to temp.

I managed to pull a few shots and the temp drops a little but now is able to recover back afterwards. I'll keep my eye on it for the next few days and update. Anyone have any thoughts as to what might have happened/be happening?

Also adding a couple pictures. In the one pic, you can see a little rust possibly forming on the thread just above the solenoid valve. The other is to show the two control boxes.





Nunas
Supporter ♡

#7: Post by Nunas »

MrBaggins wrote:<snip>I don't think it has a flow control valve on the top of the e61. It is one of the older machines with the two nuts. See picture.
Correct! Your machine has the stock e61 mushroom top with no added FCD kit.
In terms of pressure I personally haven't adjusted it at all. Can't be sure about my friend although I don't think he did either. Generally the pressure on the brew gauge wasn't jumping out at me, staying around the green marked area. But I'll double check again with a blind basket to confirm with you guys.
From your photo, I can clearly see that your machine has the older style adjustable safety valve. It's the brass thing behind the brew boiler with the big slotted screw.

Nunas
Supporter ♡

#8: Post by Nunas »

MrBaggins wrote:So quick update. Pressure wise. When pulling a shot into the blind basket, the pressure maxes out top end of the green range (10Bar I think). The screeching noise occurs at about 9bars for a second where the pressure meter also slightly falters. It's as if the water is having to force past something that is slightly stuck. I'm fairly sure it's coming from the lever mechanism as the handle also gives a little shake once the machine is able to push past to 9 bars.
Hmm. The screeching symptom you describe and its timing sounds like the safety valve is set too low, although your description of it coming from the group sounds like a missing or bad jet. Let's confirm/eliminate those two possibilities.

For the safety valve, get a marker or scribe a little line on the brass to make a note of where the screw is set. Now, turn the screw in a quarter turn and pull a shot. If the screaming goes away, that's your culprit. If not, then just move it back to the hash mark. For the jet, wrap a bit of electrical tape around the big nut atop the group and remove the mushroom with a large adjustable spanner. It should come off easily. It should be clean and bright, with no evidence of scaling. Look with a light into the end with the rubber O-ring. You should be able to see the jet. It should appear as a clean, clear sub-millimetre hole. I notice from your photo that you have an older group, with a second, smaller nut atop the large mushroom nut. You should also remove that and have a look. Inside, you'll likely find a small screen. It should be clean and unobstructed. In later machines, there is no smaller nut and no screen.
Secondly, I turned on the machine with the brew lever on for some time, approx 5/10 minutes. The group head was giving off steam but not trickling water. Then I closed it and let the steam boiler get up to temp.
This is normal. If you switch it on with the lever up, one would expect water to come out, as the pump switch is engaged by the lever cam. However, on 700/Synchronicas, no water exits (I don't know why...there must be something in the control box that does this). Note, however, that the pump may run briefly if a boiler calls for a water top-up. The bit of steam you are seeing is from the brew boiler thermosiphon; it heats the group via passively circulating water between the boiler and the group.

Nunas
Supporter ♡

#9: Post by Nunas »

I've just thought of another test to find the screaming. Given the age of the machine, and that you noticed some juddering of the group lever, perhaps the valves in the group are worn. You can test to see if there is any leakage easily. With the lever down and the machine on, depress the pump switch behind the group lever cam (I use a spoon). Repeat in the middle position. If the valves are properly seated, no water should come out in either of these two positions.

MrBaggins (original poster)

#10: Post by MrBaggins (original poster) »

Oh wow! That's great, thanks Nunas. I'll have a look when I get home and update.

Now that you said, it I have noticed a little bit of dripping happening in the downward (exhaust?) part of the group head. A few drops here and there when heating up and then maybe less concerning after pulling a shot and initially dumping pressurised water in the head. That being said it did surprise me a little, because it'll drip very gently for a few minutes post pulling. Usually means Im wiping the area under the drip tray when emptying that out.

I'll have a look at the group head valves first then see about adjusting the pressure release valve. In regards to the pressure release valve, should that turn be clockwise or anticlockwise?