Isomac Tea - no green ready light, no water from grouphead

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

#1: Post by xenobasso »

Hi all, first time here, looking to bring back to life a lovely Isomac Tea.
I was told that it was "broken" and am attempting to repair because it looks to good to be DOA.


I believe first issue was a continuous running pump that I rectified with a new GICAR NRL30/1E-2C/F control unit in place of the PRAL3. Extensive consultation with this forum enabled me to fit that. Resolved the running pump issue. :D


I now have a machine that has 2 operational red lights. Power light comes on, heating light comes on, heats up water in boiler fine then red boiler light goes off. However, the green ready light does not come on. :(
When I lift up group lever, pump appears to run (makes a noise that it is running) but no water egress from the group head. Very little water from hot water dispenser on right side and no steam from left side steam outlet.
Looking at other threads, I'm unsure if I have a blocked outlet somewhere, the boiler is perhaps overfilled or the level probe is malfunctioning? Looking to understand what the troubleshooting steps I need to carry out are.
I notice the bottom of the boiler, where the outlet is has some oxidation, so perhaps this may need opening and examination? But not sure what steps I should do first.


Appreciate any suggestions and thanks for the opportunity to participate.
Kind regards

kitt

#2: Post by kitt »

You may have scale issues by the looks of it, i wouldn't worry about the green light, they always fail on these . As long as the boiler pressure gauge shows approx 1.3, and cycles at this value on and off - the boiler is heating ok.

What does the brew pressure gauge show when pump running? May be a blockage in the top mushroom fitting restrictor . Remove the top 22mm nut and clear restriction (very small opening, 0.7mm)

Hot water - most likely pipe blocked at the boiler end, be careful with those fittings, easy to break...

Let us know what you find, be careful, work on machine cold and un plugged

xenobasso (original poster)

#3: Post by xenobasso (original poster) »

Cheers for the response @kitt.
Pressure gauge non-responsive, doesn't move when pump is running.
Weather is murder here in Perth this week, workshop is as hot as Hades so hopefully will get a chance to tackle mushroom valve on the weekend.
In the meantime,
a)what is a good descaler to use on the mush valve? I notice from the spare parts catalogue also that the GROUP HEAD JET appears to be like a gas type that can be unscrewed. Easy to do or just stick with descaler?
b)who sells a decent quality rebuild kit for the Isomac? I might as well disassemble the whole group while I'm at it and fit new seals.
Cheers,

JRising

#4: Post by JRising »

xenobasso wrote: a)what is a good descaler to use on the mush valve? I notice from the spare parts catalogue also that the GROUP HEAD JET appears to be like a gas type that can be unscrewed. Easy to do or just stick with descaler?
b)who sells a decent quality rebuild kit for the Isomac? I might as well disassemble the whole group while I'm at it and fit new seals.
Any of the commercial descalers are fine to use on solid parts like the mushroom and the brass & rubber valves in the head. Or just use Citric Acid from a bulk store. Urnex Dezcal is popular in North America, Probably equally so in Australia.
Don't unscrew the gicleur from the mushroom if you don't have a back-up handy. If it's been descaled, many times and living in bad water the threads could be seized and too easy to snap off. It's a straight hole with perfectly easy access, clean it with a welding-tip cleaner and call it done.

If you're going to rebuild the whole grouphead, I'd replace the valves complete rather than try to replace their rubber valve faces. They break off their threads easily, the cam-rider end of the preinfusion valve is going to be worn at a funny angle if it's old enough to need that much service.

xenobasso (original poster)

#5: Post by xenobasso (original poster) »

JRising wrote: If you're going to rebuild the whole grouphead, I'd replace the valves complete rather than try to replace their rubber valve faces. They break off their threads easily, the cam-rider end of the preinfusion valve is going to be worn at a funny angle if it's old enough to need that much service.
Thanks JRising for the response. I'll note the above and see what I can find kit wise for e61 groups locally. Judging by condition of machine internally, I'd say this example was hardly used so perhaps I'll get away without any changes or maybe do the "flip" trick and simply turn the seals around?

earlgrey_44

#6: Post by earlgrey_44 »

xenobasso wrote:Judging by condition of machine internally, I'd say this example was hardly used so perhaps I'll get away without any changes or maybe do the "flip" trick and simply turn the seals around?
Judging by what? If you disassemble the grouphead parts, see if the cam follower tips are worn as mentioned above. If not, you could try to flip the gaskets. They tend to glue themselves into their seats pretty good, though, you may well find that you can't.

I've replaced all the parts when leaking became an issue. Isomac sells a good number of machines where you are so somebody must be dealing in replacements.
Trust your taste. Don't trust your perception.

xenobasso (original poster)

#7: Post by xenobasso (original poster) »

kitt wrote:You may have scale issues by the looks of it, i wouldn't worry about the green light, they always fail on these . As long as the boiler pressure gauge shows approx 1.3, and cycles at this value on and off - the boiler is heating ok.

What does the brew pressure gauge show when pump running? May be a blockage in the top mushroom fitting restrictor . Remove the top 22mm nut and clear restriction (very small opening, 0.7mm)

Hot water - most likely pipe blocked at the boiler end, be careful with those fittings, easy to break...

Let us know what you find, be careful, work on machine cold and un plugged
Kitt, just an update. Its working like a champ!


E61 group completely dismantled, jet completely clogged as was screen. Was able to remove jet, descaled it and screen in weak citric. Came up as new. Lever seals reversed for now, parts cleaned in weak citric, and re-assembled. Cam profile and other brass parts of the group looked new so left them alone alone apart from a weak citric clean. Mushroom had plenty of scale that removed easily in weak citric. This seal is the one that could do with replacement. For now, re-used. Prior to re-assembly, energised machine and confirmed water flowing from group head. No water flowing before so by cleaning jet, screen, this enabled water to flow out of grouphead. This was a great morale booster!

Next:
Brew pressure gauge now working properly. Removed end closest to boiler, cleaned scale with a pin and brew pressure was able to be measured on reinstallation.
Hot water, removed boiler elbow, half clogged with scale, cleaned in citric and replaced. Working. Also dismantled wand, but it was clean.
Steam, did as above. Steam elbow at boiler completely clogged with scale. Poked and soaked in citric and replaced. Working. Dismantled wand, had plenty of sediment in there, flushed and re-installed.
Bonus. Doing all this "re-enabled" the green ready light! Wow.
Removed boiler fill probe and cleaned that. Re-tefloned the threads and re-installed, but not before using this entry point to boiler, to prime with fresh water.

Just some notes for others.
1. Wiring diagram for substitute control box, Gicar NRL30, on this forum is perfect. This fixed the initial "pump running continuously" issue. There are other threads that refer to fixing the old Pro.El.Ind box, so that might be something to try to have a spare handy.
2. When performing steps above, boiler was completed drained, and due to presence of plenty of "liquid scale" I flushed several times by filling and draining using the boiler probe orifice to feed water into boiler and rocked machine back and forth, drawing out the bottom hot/steam holes. Careful doing this as main 240V feed is right under these so took steps to ensure this covered and minimised water spillage. But with temperatures outside hovering around 42C outside, evaporation was quick!
The bottom steam and hot elbows really do collect scale. This would have to be the goto place on ANY Tea as a first step.
3. I re-installed the bottom hot/steam elbows without any thread sealant or teflon as it appeared on my example that none were used. Happy to hear from folks on whether something should be used here. As it is, these don't leak so inclined to leave them alone.
4. On re-assembly, used the top boiler fill probe orifice to prime boiler with fresh water. Then, also re-inserted the probe, and after energising system, disconnected probe, which started pump and filled boiler further. Incidentally, this also confirmed that boiler fill probe working correctly.
5. The issue to watch when re-priming boiler, as far as I can see, is that you maight overfill the boiler when doing all this causing what appears to look like the boiler fill solenoid not working, and potentially excess water being vented through the top relief valve. So I de-energised heating element and began running pump using a combination of group lever, hot tap and steam tap to bring boiler level down so as to confirm that the boiler fill solenoid worked. After some anxious moments, being careful to only run the Ulka pump in bursts of 30sec, the fill circuit activated and began filling boiler after i used the group lever, steam and particularly the hot tap.

Was an enjoyable project, that I could not have done without the help of the members here. My sincere thanks to all for your tips and responses.

Cheers,

kitt

#8: Post by kitt »

Great to hear it's working again, if you need help with parts to buy if you decide to recon the group, send me a PM .