BREVILLE BES 920 – NO STEAM – and its not what you are thinking

A bloke dropped in quite a new BES920 in pieces in a box. This is an immediate indicator that this is not a simple fix. But I had no idea how strange this one was. He told me he had done a descale, the steam boiler had failed to heat so he purchased a thermal fuse and it still did not go. So he was now officially calling it quits and could I please sort it out.

I said ok when I should have said no. I had no idea what he may have done to this machine. But I was slyly thinking. Hahah it probably just failed to refill the steam boiler. Sometimes this is easily resolved by cleaning the probes and restarting the steam pump. These machine on switch on, check the water level in the steam boiler before they activate the steam element. You can trick them to turn on the steam pump by pulling off the high water probe. The red one on the right side.

Ands that’s what I did but the steam pump did not start. I had already metered the steam boiler element at 47 ohms. So the fuse and element were both ok. So it made sense the steam boiler was empty, which it appeared to be.
Ok the steam pump must be cactus. I could hear the relay clicking but not a sound from the pump. I put my hand on it to make sure it was not quietly humming. Nope dead as a dead duck.
Now because I am old and wise I decided to double check the pump before I ripped it out. Or maybe it was because they guy looked like he was hiding a dark secret when he dropped this thing to me in a box. I connected 240V to the old pump, it bloody ran. So I connected the new pump to the wires on the outside of the machine. Switched it on and nothing but the Paul Simons sound of silence. Ok it must be a triac or the relay on the board. So I got my meter out and measured the voltage on the pump wires,240V. This cant be. Both pumps were not going and yet there was the correct voltage being switch by the board.

This was a little strange, then I thought maybe its a triac doing some strange shit. So I hooked a 60W light bulb up and turned on the machine. Sure enough the 60W light bulb lit up. So I have 240V driving a 60W light bulb at full power but I cant run a pump a tiny little 27W pump. I tried a third pump and checked the voltages while the pumps were energised. It’s true, the board would turn on the light bulb but not a pump. The only difference being was is a resistive load and the other inductive (pump coil).

In case you could not guess, changing the control board on a Breville machine is a pain. Wires need to be cut and rejoined. And this evil magic seemed to be the work of a triac to me. So I changed the steam pump triac. Not pretty but quick. It made no difference.

Yes I removed the pump thermal fuse out of the equation. A customer popped in who said he was an electrical engineer, I said good timing work this one out then. he had no idea. He said the pump might be PWM driven but it still should ramp up and drive the pump just like it was the bulb.

Anyway, I change the controller board and away the pump went. Now I putting this down because this could happen to you. And I know what you are going to do when the pump is not going and appears to have 240V getting to it. And these pumps are not cheap and I’ll charge you a restocking fee. Amazon won’t even take it back. So my sage words of advice. Check the old pump with 240V before you order a new one. It might be Gremlins on the power board causing the issue.



The steam boiler is not heating but the element and fuse both meter ok
Despite 240V being switched to the pump, not even the replacement pump will run.
The 60W bulb lights but the pump wont run? what the hell!

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