laimeduck Posted November 13, 2011 Share Posted November 13, 2011 A few weeks ago I drained down the water system in my van by opening the electric drain valve on the Truma boiler & also manually drained the fresh water tank. I left the truma valve in the drain position i.e. “open”. I tried to start the van 2 weeks ago & the battery was flat, so I had to jump start it. (The battery is in good condition & has given no problems before) I did, & took the van for an hour’s drive. Rather than just rely on the solar panel, which has kept everything Ok during the summer, I then connected the EHU. Last weekend I tried to start the van, but the motor battery was again flat? I again jump started the van & ran it for a while. I thought about it, & the only change I had made was opening the Truma drain valve. So I closed it again. Yesterday I started the van with no problems - the battery is behaving itself again. I am confused! Why would this electric valve drain the battery? Is it drawing current in the open position? Is this why people use a clothes peg to keep it shut? Has anyone got any ideas - words of one syllable please, I am an electrical dunderhead! Link to comment Share on other sites More sharing options...
bolero boy Posted November 13, 2011 Share Posted November 13, 2011 I'm fairly sure that, with the valve in the open position, a small pump is driven to expell the water from the Truma. On mine you can just about hear it running. By leaving the valve open you are effectively running a small water pump all the time hence the draw on the battery. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 13, 2011 Share Posted November 13, 2011 bolero boy - 2011-11-13 10:04 AM I'm fairly sure that, with the valve in the open position, a small pump is driven to expell the water from the Truma. On mine you can just about hear it running. By leaving the valve open you are effectively running a small water pump all the time hence the draw on the battery. I can't comment on the noise you've mentioned, but a Truma C-Series heater is not fitted with a pump to expel water. The electric safety/drain valve fitted to Truma C-Series heaters draws a tiny amount of 12V power when it's CLOSED. That's why Truma advises that the valve be opened if the leisure-vehicle is to be out of use for an extended period. When the safety/drain valve is OPEN it draws no current (or at least it shouldn't!). Even if the valve is inadvertently left CLOSED, its current-drain is so small that it would take ages to flatten the leisure battery. Which comes to the 2nd point - it's extremely unlikely that a Truma safety/drain valve will take its 12V power from a motorhome's STARTER BATTERY, so - even if there's a fault with the valve - it should not affect the vehicle's starting capability. Whatever is causing laimeduck's starting problem, it ain't the drain-valve. Link to comment Share on other sites More sharing options...
tugga Posted November 13, 2011 Share Posted November 13, 2011 We had this problem Laimeduck, we couldn't start our motorhome and the battery was completely flat. It took us a while to find the culprit and it was the radio. Although we thought we had turned it off, I don't think we could've done and we didn't remove the front like we usually do. We put the flat battery down to the radio drawing current from the starter battery. We now make sure that the front is removed and are very conscious of doing it and we have not had a problem since. Just another view with a possible cause. Link to comment Share on other sites More sharing options...
Guest 1footinthegrave Posted November 13, 2011 Share Posted November 13, 2011 Do a Google search for "Battery parasitic draw",I had this issue on a car once. Turned out to be the alternator,that although charging fine was leaking current back when stationary. As others have said it is unlikely that the drain valve would be on your engine battery circuit even if it was faulty, assuming that is you have a leisure battery fitted that is. Link to comment Share on other sites More sharing options...
bolero boy Posted November 13, 2011 Share Posted November 13, 2011 Derek Uzzell - 2011-11-13 10:22 AM bolero boy - 2011-11-13 10:04 AM I'm fairly sure that, with the valve in the open position, a small pump is driven to expell the water from the Truma. On mine you can just about hear it running. By leaving the valve open you are effectively running a small water pump all the time hence the draw on the battery. I can't comment on the noise you've mentioned, but a Truma C-Series heater is not fitted with a pump to expel water. Derek, sorry but I didn't say that we actually have the Truma Combi 4E and the sound following the lifting of the yellow valve may just be running water.................... Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.