ALDE 3020 Pump Issues

acwilson

 2022 Tab 320s
Is there a unique fuse for the glycol pump in the 3020?
I was getting hot water but no heat about a month ago.  I couldn’t get the glycol pump to turn on, even through setting it into continuous mode. I took it to a Truma authorized service center and they replaced the pump.  I picked my trailer up this morning. Service rep told me that the techs had tested everything and it was working fine. I get it home and I still can’t get the pump to turn on.  There are no error messages on the screen, the glycol is heated up to 170 F.  I have the heat cranked up to 80, and it’s 50 outside and inside the trailer. I opened the overflow expansion access and the glycol in it is cold.  So the glycol is definitely not circulating. 

I bought my trailer new and have done the glycol changes as directed every two years. Last change was this summer. I hadn’t used the heat until last month when I needed it, so I’m not sure if the pump ever worked after the glycol change. 

qhumberd

@acwilson If there are no errors on the control panel you can easily test if the circulating pump turns on by setting it to Cont and seeing if the icon shows up on the screen. I can’t find a fuse reference to just the pump. If that doesn’t light up then call back the technician who replaced the pump.

If the Cont setting turns on the icon then the pump settings can be checked on the pump itself.   2-3 is the normal operating setting. It might be turned all the way down.

Final idea is an air block in the loop preventing flow. Try turning the pump to 5 to clear this. This setting should cause visible churning in the reservoir tank, confirming the pump is working.

If all this fails then back to the technician or email Truma. Found one fuse thread with the Truma email here 

https://tab-rv.vanillacommunity.com/discussion/18269/alde-3020-thermal-fuse

pthomas745

A while ago, a person on the FB page looked closely at their "new pump" that wasn't working and discovered it wasn't plugged in to the correct spot on the circuit board.  

Open the Alde area, and open the "Service Hatch" and make sure the cable is connected to the proper spot on the circuit board.  In the Alde 3020 manual, you will find this schematic. It may also be pasted to the bottom of the Service Hatch  Check to make sure the cable for the pump is properly connected there next to the fuse.

acwilson

Thank you!
Continuous setting doesn’t get the pump going. 

It is currently set to 3.  I have the nose of the trailer down, trying to encourage any bubbles to work their way up to the bleeder valve. 

I’ll try turning it up to 5.  

I’m worried the control board is the problem. 

qhumberd

Can you feel it running at all?

acwilson

No.  The pipe running out of the pump is cold. 

acwilson

I really wish it was plugged in to the wrong place.  I don’t see anywhere it could be plugged in except maybe the 12v plug.

Grumpy_G

If you have a voltmeter you can stick the probes into the pump connector from the back. That will tell you if the control board turns on the pump. 
Also there is a reset procedure (actually two) for the Alde system. In the settings menu of the screen on page 4 should be a reset button. Or disconnect both shore and battery power for 10+ minutes supposedly works too. 

qhumberd

acwilson said:

No.  The pipe running out of the pump is cold. 

In the original post you mentioned that the pump itself was not turning on. if you can get a hand on the pump you should be able to feel it running. If it is running and the pipe is cold that would suggest to me an air block in the loop. If you can't feel it running then it would be back to checking the control board as @Grumpy_G suggested, since the tech indicated they replaced the pump. Your picture shows the plug to the R of the green fuse as the power to the pump, and that looks correct.

acwilson

I’ve had the nose down >24 hours, the bleeder valve is open.
The pump is turned to continuous and set to a speed of 5.
The outlet the pump plugs into reads 12.5 V.
I did a hard reset unplugging the 12V and shore power for 30 minutes. I also did a reset off the control screen.
I still can’t get the pump to turn on.  

I will try emailing and calling Truma. 

Thanks for y’all’s input. 

Bayliss

@acwilson, I am interested in hearing what Truma suggests, so following.

It sounds like a power issue to me.  Maybe inspect the length of the wires along the distance from the from the circuit board where the cable plugs in, and down to the pump, looking for any breaks or damage to the wiring (although I believe the two wires may be covered with an electrical wrap, so not visible).  With AC/12V connected, jiggle the wires at the pump to see if anything happens.  Also, maybe probe the two wires with a multimeter to determine if power is present where the wires enter the pump.

acwilson

I haven’t heard back from Truma.  The repair people want it back, so it’s going in the morning. I’ll let you all know what they find. 

The pump is hardwired to the plug, so I’ll have a hard time testing the wires. What I think is interesting is that the new pump has extra wires that they’ve cable locked out of the way. Original pump only had one set of wires.  First pic is how it looked before going in for repair.  Second one is now.  

pthomas745

@acwilson That extra pump connector is very interesting!  In the 400's, there are two glycol pumps.  One pump is for the main Alde heater.  The other pump is set up for the Alde Flow tank.  If you look closely at the Alde schematic that is posted above, there is an inset for an "Optional Board" which is installed in the 400's.  I'm not sure which connector exactly is the one for the Alde flow pump, but there is one slot connector noted as "Alde Flow".  Wild guess: they connected the wrong cable to the connector for your pump.

And, I found an Alde Flow installation .pdf.  In this document, the connection marked "Alde Flow" on the schematic above is clearly marked as "Extra Hot Water Pump".  

https://products.alde.se/storage/media/15554074845cb5a27cef5b9/v-302019-rev1636-installationsanvisning-alde-flow.pdf