E61 Rocket pumping non-stop but not heating

[Johnnz]

To recap from the related thread I tagged onto, when unit is switched on the pump keeps running but no rise in gauge pressure or heating of boiler. There is no power to the element when checked with multimeter.
I have just opened up the head and everything is very clean with minimal corrosion and no scale.

Talk Coffee suggested "thermal switch, element or most likely a dead control board".

I'll be able to check the thermal switch next time I'm in my workshop. Is there any need to check the solenoid still or can that be ruled out? It had 230v across so has power but not sure about correctly functioning.

I will attach a photo of the control box. I read somewhere that some models require a modification or replacement. Is it possible to tell from this photo whether or not this should be replaced too?

Thanks for the help.

[IMG][/IMG]

[IMG][/IMG]

[TC]

Nasty, nasty. I hope your wife paid about nothing for it as this is one serious roughie.

It must be one of the very earliest ever built as they haven't used an RL30 for a good 10 years. To upgrade to a current board requires loom modification or replacement.

There is clear evidence of leaks and it's probably time the machine was restored or sent to the big scrap factory in the sky. It's pretty clear there are multiple issues which would need to be resolved here and will require $$$.

I'd be looking for money back. There is no way this was recently serviced by any tech who should still have a job. One for Mr Caveat Emptor.

[Johnnz]

Nasty, nasty. I hope your wife paid about nothing for it as this is one serious roughie.

It must be one of the very earliest ever built as they haven't used an RL30 for a good 10 years. To upgrade to a current board requires loom modification or replacement.

There is clear evidence of leaks and it's probably time the machine was restored or sent to the big scrap factory in the sky. It's pretty clear there are multiple issues which would need to be resolved here and will require $$$.

I'd be looking for money back. There is no way this was recently serviced by any tech who should still have a job. One for Mr Caveat Emptor.

That's not a very encouraging analysis :-(
Though not clear in the photo, most of the water staining on the base panel came from the nylon pipe that exits the pump where it joins onto the 'T' joint. It was this point where I disconnected and confirmed pump operation and rejoined it without further leaking.
Although seals are in need of replacement in the group at least there is almost no scale and very little corrosion so it has at least been looked after to an extent. I'm not sure if the innards of the tank and heat exchange etc have been looked after as well yet though.

I took apart the control box and inspected it and there are no cold joints or burnt out components noticeable. Noidle22 suggested a faulty signal transistor(s) so I may replace those in the hope of an easy fix. To help troubleshoot though I would appreciate feedback on the current function of this unit:

Power on --> within a second a click can be heard from a relay in the control box followed by a 4 second delay until the pump starts operating. No power supplied from control box to element circuit however.

Water pumps and cycles through reservoir.

If the group arm is pulled up water comes out of the shower.

Solenoid has power and when isolated has an impedance of 2.5k ohm.

Element has resistance of 44 ohms.

Thermal switch and pressure switch are both closed.

Pump doesn't stop until unit switched off at mains or power switch!

Perhaps this information helps deduce the source of the problem further?

[LeroyC]

That's not a very encouraging analysis :-(
Though not clear in the photo, most of the water staining on the base panel came from the nylon pipe that exits the pump where it joins onto the 'T' joint. It was this point where I disconnected and confirmed pump operation and rejoined it without further leaking.
Although seals are in need of replacement in the group at least there is almost no scale and very little corrosion so it has at least been looked after to an extent. I'm not sure if the innards of the tank and heat exchange etc have been looked after as well yet though.

I took apart the control box and inspected it and there are no cold joints or burnt out components noticeable. Noidle22 suggested a faulty signal transistor(s) so I may replace those in the hope of an easy fix. To help troubleshoot though I would appreciate feedback on the current function of this unit:

Power on --> within a second a click can be heard from a relay in the control box followed by a 4 second delay until the pump starts operating. No power supplied from control box to element circuit however.

Water pumps and cycles through reservoir.

If the group arm is pulled up water comes out of the shower.

Solenoid has power and when isolated has an impedance of 2.5k ohm.

Element has resistance of 44 ohms.

Thermal switch and pressure switch are both closed.

Perhaps this information helps deduce the source of the problem further?

Are you based in NZ somewhere John? Who did this supposed repair.

[Johnnz]

Are you based in NZ somewhere John? Who did this supposed repair.

Hi Leroy, yes I am in Queenstown. The machine was bought off Trademe from Christchurch. When the seller said "recently serviced" I think they just meant electrically safety-tested My wife bought it on a bit of a whim without really digging into its service history...
Anyway, as I said, it appears reasonable condition for it's age though does require new seals - if it will be economical to repair...

[noidle22]

Another thing to check, unplug your autofill probe and earth it. Does the pump stop? If so, the autofill could be faulty.
The boiler fill solenoid should activate if the control board thinks the boiler needs water, see if you can hear it click or measure the voltage at the coil when the pump is running and see if there is 240V present. You mentioned that the solenoid has power, was that the boiler fill solenoid?
You seem to know your way around a multimeter and most of the machine but be careful when measuring 240V components.

I do seem to remember now that on my fiend's Giotto, everything powered up when the machine was switched on, the pump and element. Slightly different case to yours but the fault may still be the same.

[Mouldy]

This link to HB seems as though it may have some relevant info. There is reference to the RL30 control box as the new unit replacing old. There is also some suggestions on some alternative fixes that may be interesting. The link also contains a pdf link to a Giotto manual including electrical schematic of the control board connections etc.

http://www.home-barista.com/espresso...ad-t17616.html

As Noidle22 suggests, it is worth investigating the boiler level fill probe and solenoid. If the machine thinks it has no water (i.e pump keeps running trying to fill boiler) then it may also inhibit power to element so that it is protected from burn out? That you have measured 44ohms resistance across the element suggests it is ok.
Good luck.

[LeroyC]

Hi Leroy, yes I am in Queenstown. The machine was bought off Trademe from Christchurch. When the seller said "recently serviced" I think they just meant electrically safety-tested My wife bought it on a bit of a whim without really digging into its service history...
Anyway, as I said, it appears reasonable condition for it's age though does require new seals - if it will be economical to repair...

Hi John, it shouldn't be hard to track at least it's most recent service. There are only two places in Christchurch that can do full repairs and servicing - Gary Lee Electrical and Espresso Tools (the service side is called Coffee Tech I think). Gary Lee tag everything so if they did it you'll see a sticker or tag. I would imagine Espresso Tools do too so if there's no tag then it probably wasn't either of them. The most likely alternative for a Rocket would be C4 as they do basic servicing, but a couple of the other roasters do as well like Switch and possibly Hummingbird.
Even if there's no tag or sticker you could try calling the service centres to see what they can tell you. They should be able to find records for your machine using the serial number if they actually worked on it.
There's been a few Rockets on Trade Me lately. Most go for a bit of a premium. Hope yours was a reasonable deal and you can get it going. Good luck.

[Johnnz]

Another thing to check, unplug your autofill probe and earth it. Does the pump stop? If so, the autofill could be faulty.
The boiler fill solenoid should activate if the control board thinks the boiler needs water, see if you can hear it click or measure the voltage at the coil when the pump is running and see if there is 240V present. You mentioned that the solenoid has power, was that the boiler fill solenoid?
You seem to know your way around a multimeter and most of the machine but be careful when measuring 240V components.

I do seem to remember now that on my fiend's Giotto, everything powered up when the machine was switched on, the pump and element. Slightly different case to yours but the fault may still be the same.

Hi again,
Right! So, removing and earthing the autofill probe causes the pump to stop and element to power up after a few seconds delay.
I have now taken out the probe and had a look inside the tank with a torch and it looks reasonably clean. A little corrosion but no flaking at all. So now I have to nut out why the sensor isn't working inside the tank and if indeed the pump is able to push water in there or not...

I am more confident now that the control box is functioning properly (unless the earth signal is too weak for it to detect through the water), now I am begining to suspect a faulty solenoid...

[Johnnz]

Right, probe out power on, pump runs but no water entering boiler. Must be the solenoid. It has power so must have an internal fault.

[Johnnz]

Just tipped all the water out of the boiler through the probe fitting. So much sand came out too! I wonder if during transit some sand fell down into the solenoid to block it or the pipe attaching it to the boiler...

[Mouldy]

Hi again,
Right! So, removing and earthing the autofill probe causes the pump to stop and element to power up after a few seconds delay.
I have now taken out the probe and had a look inside the tank with a torch and it looks reasonably clean. A little corrosion but no flaking at all. So now I have to nut out why the sensor isn't working inside the tank and if indeed the pump is able to push water in there or not...

I am more confident now that the control box is functioning properly (unless the earth signal is too weak for it to detect through the water), now I am begining to suspect a faulty solenoid...

Sounds like you're making progress.

Have you checked and cleaned the level sensor connection points and terminals?


What was the approximate boiler fill level when you looked in the tank? Sounds like the boiler fill solenoid valve if the pump was running constantly yet the boiler wasn't overfilled. Your success in earthing the fill level probe seems to suggest that the boiler is actually too low on water (so it's telling the pump to fill the boiler), but if the fill solenoid isn't working correctly then it can't do so.
Is there a line down stream of the boiler fill solenoid that you can disconnect to verify function of the valve?

[Johnnz]

Took the solenoid off. The brass plumbed section looks clean. When tested with power on there is no sound of a click or anything. Still not sure if electrical fault or mechanical in brass fitting but leaning toward mechanical as there is 2500 ohm resistance in coil.

[artman]

Is it the type of solenoid you can take apart and see if the plunger is stuck?

Cheers

[Johnnz]

Sounds like you're making progress.

Have you checked and cleaned the level sensor connection points and terminals?


What was the approximate boiler fill level when you looked in the tank? Sounds like the boiler fill solenoid valve if the pump was running constantly yet the boiler wasn't overfilled. Your success in earthing the fill level probe seems to suggest that the boiler is actually too low on water (so it's telling the pump to fill the boiler), but if the fill solenoid isn't working correctly then it can't do so.
Is there a line down stream of the boiler fill solenoid that you can disconnect to verify function of the valve?

The water level was just below the bottom of the probe.
By removing the autofill sensor I could see directly through to the boiler fill fitting at the bottom. No water came through however when pump was on.