Dream T group head boiler not primed?

[bakon333]

Once the machine reaches temperature on both boilers, it takes 10 seconds for water to come out of the group head once the brew button is pressed.
At which point, the temperature drops from 201 to 175. And I have to wait a few more seconds for to rise back to 201 before pulling a shot. For years, I've never had this problem. I usually get water and full pressure at any time.

If I continue to pull shots at this point, it works fine. But if I leave the machine on for a few hours and come back...I have to wait another 10 seconds and start over.

Anyone have a clue what's going on? Hoping it's an easy fix.

[bakon333]

No one?

[chas]

I've never owned a tank model. Fortunately, 90% of the design is the same as the plumbed models. Unfortunately, it sounds like your issue is likely with the other 10%. The only thing I can think of is that the valve at the tank that prevents water from flowing back into the tank has failed so that water is flowing out of the boiler and/or the water lines and back into the tank.

You can check for this by removing the tank after pulling a shot and see if water leaks back into the tank compartment before you pull the next shot.

If that's not it and no one else checks in, you may want to talk to the LaSpaziale tech at Chris' Coffee Service.

[Velcro]

let us know how you resolve the problem. I'm curious if the issue is in the 90% that matches the plumbed in or not.

[goodboyr]

Take a look at page 11, part 7407 on this diagram. It's the non return valve that Chas is talking about. If it passes, it will allow water to drain back out of the pump back into the tank. It appears to be the only non return valve in the line all the way to the boiler.


https://shopify-er.s3.amazonaws.com/res ... akdown.pdf

[bakon333]

Wow, thank you for your responses. Very helpful.

Well there is indeed dripping at the non-return valve. It's not huge but it's there. I'll try to repair this and get back to everyone. This part should be at Chris' Coffee? Might just be that 10% Chas was talking about lol. (crossing fingers)

[chas]

Not sure how much dripping is enough to cause a problem. If it is enough to lose the prime that's all it might take. Also, I would imagine at least a few drips would come out each time you removed the tank but that shouldn't be enough to lose prime.