SylvainMtl wrote:Also this 4.5 bars is the pressure shown when the boiler refills. I have the feeling something is wrong, that the pressure should go back closer to 2 bars after turning off the pump.

Maybe I should start a thread about this issue.

Don't bother. The pressure is low on boiler fill because it's (nearly) unrestricted flow--the pump doesn't come to full pressure. Then the machine cuts the pump and the fill solenoid in synchronization, and the pressure is "frozen" at 4.5 bar (or whatever). If you have a check valve installed on your pump outlet (always a good idea, though my 1999 Elektra didn't come with one), it will stay that way till you relieve the pressure in some way. If if doesn't have the check valve, it will most likely drop back slowly... most rotary pumps allow backflow (which would relieve pressure), but in my experience they resist it. It's probably not good for them. Certainly, LM and Synesso do, and IIRC Stefano suggested it to me as a good idea.

I don't have a check valve on the pump outlet. But I seem to remember the behavior I'm describing was absent before I changed the original pump for a procon. So it maybe a function of the procon resisting more to the backflow.

Sylvain -

Your check valve MAY NOT be located at the pump outlet. It is TYPICALLY located in the line leading to the hx inlet because the only other recipient of the pump's flow (the boiler fill) is inherently "protected" by means of the fill solenoid valve. It is usually a piece of hex brass about 1.25 inches in length with 1/4" BSPP fittings or threading on the ends.

You're right, Eric--I forgot. The Elektra's check valve is on the outlet of the 4 way junction (inlet, pump fill, pressure gauge, brew line) that is going towards the flowmeter (or on an A3, presumably the HX inlet directly). So, the brew pressure gauge is on the pump side of the check valve. That's fair enough; it keeps it from registering 11-12 bars at idle like a Synesso or LM. I'd still imagine pressure is registering higher than line on Sylvain's gauge is because of residual pressure from the pump resisting back flow.


Here it is, behind my inlet hose... the fitting going out to the copper line on the right.

OK who can make me or where can I buy the capillary tube? Can I make one? I can solder it in no problem but bending tubing is not my specialty
Thanks!

I just bought 1/16" tubing adapters from Swagelok for my gauge line (which is actually broken and has been for some time). Bending copper capillary line is pretty easy, at least the 1/16" OD stuff.

When I made a pump pressure gauge for my Isomac long ago, I used 1/16 inch copper tubing, put the ends on it and to coil it I wrapped it around the handle of a large screwdriver.

My A3 has some needle flutter at the beginning of the shot. I know when I choked a shot just by the action of the needle. But it only does that for about 4 seconds then levels out. Sounds like you are getting a lot more flutter than I am.