Long post below - how to install drain valves on an Evo Leva, expanding on the inspirational post by LMSC
(note: nero.co.uk also has the valves, but they are much more expensive than from PipeworkSuppliers. They are also available from even cheaper suppliers based in China, but they will take a much longer time to arrive)
Heat service boiler to normal temperature, switch machine off, then flush boiler through hot water valve.
Disconnect from power and let machine cool down
[** remove top panel of machine using 3 mm Allen key, disconnect temperature sensor wires (and remove cable ties before connector), then remove temperature sensor from brew boiler using a 17 mm open wrench - and syphon/syringe out as much water as possible, or see alternative method at points 9. and 10. below]
Remove water tank
Put machine on its back
Remove inspection panel, using 3 mm Allen key to remove bolts
Remove electrical connections to heating element on brew boiler (you may need to use a pair of long-nose pliers)
Slacken plug on bottom of service boiler with 6 mm Allen key. A fair amount of force will be needed, as it has been secured with thread locker. Use an impact driver if you have one, or insert a tube wrench on the Allen key shaft to increase leverage. Go slowly. Do NOT use rounded/ball Allen keys on the plug, particularly for the brew boiler – the opening is very shallow, and the plug is in brass, so quite soft, and it is easily rounded if the key doesn’t have a good grip. A towel may be useful to catch any remaining water and to protect the heating element terminals/connectors in case the tool slips.
** slacken plug on bottom of brew boiler with 5 mm Allen key. Same warnings as above re: force required, proper type of tool etc. - this one is smaller and much easier to damage, plus the connectors are really close to the plug. If you haven’t emptied the boiler in point 3. above, do NOT remove the plug, just slacken it and re-tighten it so it can be easily undone, but it doesn’t leak (much) - the boiler is still full.
** Straighten up machine and place on ‘something’ to raise it (books/pieces of timber/bricks/plastic boxes - remember, it’s heavy!) Place a container that holds at least 1 litre under the brew boiler, and remove the plug from the brew boiler, draining it completely. If you do this, you may as well remove the plug from the service boiler next and remove any remaining water (there will be very little, if you had good pressure when flushing it from the water tap). Put the machine back on the work surface, and lay it on its back again.
Note: the brew boiler may not drain easily without creating a way for air to enter - the easiest way to do so is to remove the temperature sensor from the top of the boiler. You will need a 17 mm spanner to do that (and something to cut any cable ties - the wires need to be free to rotate as you undo the fitting)
Prepare the parts for the service boiler drain valve. Put generous amount of PTFE tape on the male fitting of the valve (remember to wind the tape in the same sense as you will then tighten the fitting, so it won’t unwind when you screw it in), then remove the lever.
Clean the threads of the boiler tap with the scouring pad from any thread locking compound residuals. Thread the valve in by hand until it feels tight – then give it a further turn or so with the 21 mm socket wrench - don’t overtighten, but make sure that the lever will be easily accessible by hand. Be careful that the electrical connections to the heating element are quite near and could be damaged when screwing in the valve. Re-assemble the lever and the locking screw on the valve. Make sure the valve is closed (easy to forget…)
Thread the push-fit adaptor on the other end of the valve and hand tighten it. It doesn’t need tool tightening as there is no pressure (and it has an o-ring to provide sealing)
Push the tube into the push-fit connector – it has to go in about 15 mm or ½” and cut to the desired length. If using John Guest push-fit connectors, it is possible to remove the pipe easily and without tools (just hold the collar in against the connector’s body with fingers/pliers while pulling on the pipe), so you may want to keep the pipe stored somewhere else and just fit it in when draining the boiler.
Check that the valve is closed. If you only wanted to fit the drain valve to the service boiler, go to step 21. You may want to give the boiler a flush with cold water using your newly-fitted valve, before closing the inspection panel on the bottom, to get rid of any scouring pad and thread-locking compound residues.
** Prepare the parts for the brew boiler valve. Wind PTFE tape on all male threads. You do NOT need to remove the valve lever here.
** Assemble the ⅛” x ¼” adapter, the nipple and the elbow. Tighten the fittings well using the 16 mm socket and the 5 mm Allen key as in the illustration below. I also used the water pump wrench to tighten the nipple, as it wasn’t as tight as I wanted it just by winding the two other fittings onto it.
** Clean the brew boiler tap thread with the scouring pad. Thread the assembly into the tap by hand, then tighten using (alternately) the water pump wrench and a small Allen key (or a stubby screwdriver) inserted into the elbow connector. It is not a pleasant task as the space is very tight, and the stainless steel body of the machine has sharp edges; prepare for a few scrapes. Sorry for the poor quality photo - it’s by far the most physically difficult step of the whole process.
** Thread the valve onto the elbow, ensuring that the valve lever ends on the inside of the machine, otherwise you won’t be able to close the bottom panel. Tighten as required with the 21 mm socket, but be careful not to overtighten (the whole assembly is still threaded into the relatively thin boiler bottom plate). Make sure the valve is closed.
** Thread the push-fit adaptor on the other end of the valve and hand tighten it. Fit pipe as required (or leave it off until you need to drain the boiler).
Re-fit the electrical connectors to the brew boiler’s heating element.
Before closing the bottom panel, test that there are no leaks. I rigged a ‘bridge’ with my coffee trolley and a kitchen cabinet (which ‘coincidentally’ are the same height… but you could use anything to raise the machine and get enough space to fit a tray/container), straightened up the machine, re-fitted the tank, switched off all heating elements from the control panel and filled both boilers, then waited for 30 minutes to see if there were any leaks (yes, there were - I hadn’t tightened sufficiently the elbow fitting . One more turn required, which necessitated removing the fittings, re-doing the PTFE threading and re-tightening everything).
Note - if you need to empty the brew boiler from cold, you may need to remove the temperature sensor from the top, as it is typically filled very high and it quickly creates a vacuum that prevents the exit of further water from the drain valve… of course only until you tilt the machine, at which point it pours out! If you do end up removing the temperature sensor, be very careful not to twist the wires (remove cable ties and disconnect the push-fit connector). Re-fit and replace the cable ties once you have eliminated ‘cold leaks’ before proceeding to the next step.
Pressure testing - heat relevant boilers to 130 °C keeping a very careful eye for any leaks (switch off everything if you see water or steam!). Emptying either boiler when pressurised is very easy, through the drain valve… be careful as there will be highly pressurised hot steam and water coming out. Use gloves and fit a long pipe ending in a drain or a deep saucepan - do not use plastic containers!
Re-fit the inspection panel (either from under the ‘bridge’ or by re-tipping the machine on its back).
Clean up the plugs, wind some PTFE on the threads and store with your other spares, in case you want to remove the valves at any point. Finished!
