Solar heating not work - Solar pump does not start automatically

larbakium

Hi,
noticed that my solar system is not heating up the water. After trying to get my head around it, is seems that the solar pump is not starting according to the automatic schedule on the solar controller. here is more details and the list of components at the end of the post.

When I look at the controller, I see temp of the solar panels, temp of the top of the cylinder and the bottom. The automatic timer icon is displayed and all factory defaults setting are ok. (meaning the pump should start at 0700 until 2200).
1. the temperature on the top of the cylinder shows a steady 320 degrees celsius.. which call my attention for a problem.
2. temp on the bottom of the cylinder is at 14 degrees...

One of the buttons on the controller starts manual operation of the pump. When I do that, I can hear water flowing. the solar panel temp starts to decrease and slowly the temp on the bottom of the cylinder goes up. The top of the cylinder stays at 320.

I tried to do a reset of the controller, but I am not sure I am successful, as the manual suggests to use the same button that starts manual operation and every time I try to reset, I get no confirmation it has reset, but instead the manual operation kicks in.

I am thinking if it is possible that the pump does not start in auto mode because the controller thinks the top of the cylinder is at 320 degrees.
I tries to find the manufacturer of that controller, but its nearly to impossible.. I find manuals to similar controllers, but not mine. The controller box and the original manual printout do not state manufacturer or model of that thing...


Any ideas? or my logic is completely wrong!!

List of components:
Cylinder: Vokera AquaFlow 300 TC Twin unvented twin coil water cylinder
Solar pump: Grundfos Solar 15-45 130
Solar controller:Control Bos Sun B (Differential controller) - single digit screen/ No model
Expansion vassel: CIMM Solar 18L

dathi

possible that the solar temperature sensor is broken on cylinder http://www.ebay.co.uk/itm/Remote-temperature-sensor-with-3m-cable-TR-PTR-VS-PU-LS-solar-charge-controllers/112489909893?epid=1705540752&hash=item1a30ebce85:g:bEgAAOxyY9VRMn8t

rolion

Have you checked the wires ?
Could be a short as well,before buying a new sensor.

Most of the local shops should have one in stock.
Go with the old one,make sure is the same type / impedance ,specifications.

larbakium

Update:
yes, the problem seems to be with the sensor. replacing the bottom sensor does bring the temperature on the screens.
Is there any particularity I should look for when buying a sensor or its all the same?

also, have you worked with this type of controller? I am wondering if this is actually the root of the problem or might be something else cause the solar pump not to come on at the timer.


Thank you

Thank you both,
I am not sure I feel comfortable to remove the wire. I would have to open the controller box.

Do you think this would be a job for electrician or plumber? In the past I have been in contact with plumbers that say they don't do any solar systems. So, I am not sure who to go. What is your views?

::::::

larbakium

Where would I be able to find these sensors locally? Local hardware shop or these would be best found at plumbing center or Electrical warehouse?

Thank you

larbakium

larbakium wrote: »

Where would I be able to find these sensors locally? Local hardware shop or these would be best found at plumbing center or Electrical warehouse?

Thank you

Hi. just noticed i didnt close this conversation. the sensor was the part causing the issue. Replacing it resolved. Thanks for all the help.