[NWH]

I do that sometimes also the water gets really hot then though lol,when the battery output reads 14.5 the water on start up is burning hot.
As said starting the heater with engine off of the batteries are oldish the heater can turn off.

[Spruce]

Webasto heaters will automatically switch off if the battery voltage drops to 10.4v. The way to see if it is the battery is to put a multimeter across the terminals on the voltage setting and switch the heater on. If the voltage drops to the mid  10v then its a battery related issue, especially if they have been on charge all night.

[dazmond]

We have done the following and it helps
Whilst it’s still plugged in to the grippa charger we start the heater, leave it on fir 5 mins, unplug and drive to jobs
I’ve found by using the spare pump (twin 9kw heater fitted) at say a pump setting of 10, it’s constantly recirculating all day and then the heater won’t shut down, which is what sucks a lot of battery juice .
Just my findings
Also daz think your a bit premature with replacing, unless grippa said so....

Mr B

It's got to be the batteries as the low power fault code only shows up after 6 hours running NOT if it's been running for 3 or 4 hours and then shutting down.....

[dazmond]

Webasto heaters will automatically switch off if the battery voltage drops to 10.4v. The way to see if it is the battery is to put a multimeter across the terminals on the voltage setting and switch the heater on. If the voltage drops to the mid  10v then its a battery related issue, especially if they have been on charge all night.

I think nigels batteries will be well and truly knackered then if they've dropped that low!

[NWH]

These haven’t dropped that low they did before I got the mains to van charger though,I think mines down to the batteries needing to be replaced.

[dazmond]

well.......today i had the heater running again for 6 hours and it was absolutely fine....water piping hot and no low power fault code when shutting down at 3pm.......the only thing i can think of is i did a bit more driving around this afternoon which must of topped up the batteries a bit...the water was that hot i couldnt put my hand under it this afternoon.....strange.....voltage reading of 12.5 when shutting down too before going up to 12.8.....its never been that high at the end of the day for ages....

lots of times over november/december ive noticed the fault code flashing when shutting down at the end of the day and this is despite keeping my engine running at lunchtime for half an hour (with the heater still running)this is usually on days where im parked up for hours on end......the voltage reading is 12.2 before going back up to 12.4 once heater has completed its 3 min shut off cycle......

[NWH]

If my heater shuts off after I’ve started it even with an overnight charge the red led on the side flashes about 3 times pauses and same again,if I drive turn the heater on before when the vans running when I get to the next job it’s working fine and continues to do so the rest of the day.
My issue I’m sure is the batteries due to it drawing a huge amount of amps on initial startup,if I plug into the mains and start the heater up obviously van not running it purrs like a dream with 14.5 volts on the meter,nice to hear your heater is producing something like hot water Daz lol lol.

[dazmond]

If my heater shuts off after I’ve started it even with an overnight charge the red led on the side flashes about 3 times pauses and same again,if I drive turn the heater on before when the vans running when I get to the next job it’s working fine and continues to do so the rest of the day.
My issue I’m sure is the batteries due to it drawing a huge amount of amps on initial startup,if I plug into the mains and start the heater up obviously van not running it purrs like a dream with 14.5 volts on the meter,nice to hear your heater is producing something like hot water Daz lol lol.

it must be your batteries mate....my heater has never turned off due to low power and im replacing mine this weekend!

[NWH]

Yeah I know it’s the batteries m8 I’ll probably get the same as Splash he has BBL batteries

[dazmond]

Yeah I know it’s the batteries m8 I’ll probably get the same as Splash he has BBL batteries

how long is your heater running on an average day nigel?mines 6 hours.......you also have a split charge relay fitted i gather?and bench charge overnight?i seem to remember you getting your grippa heater fitted around a year after mine meaning the batteries are only just over a year old....

[NWH]

At least 6 hours yeah much the same,if I’m doing a job that the hot will crack I’ll turn it off return to tank to cool the plates down first then turn it back on,this doesn’t effect the heater turning off though once it’s running it’s fine it’s just first thing in the morning when you need good batteries.
The first switch on it requires good healthy batteries or it will shut down,it doesn’t just have to be voltage as low as 11.10 the better the batteries the hotter the water you’ll get in my experience.

[dazmond]

ive had my heater on for 5 and a half hours today and the low power fault code came on again when shutting it down  this afternoon.......it was fine yesterday and it was running for 6 hours......i cant work it out......

i spent 3 hours parked up (like yesterday)and a few little drives this afternoon.....water was fairly hot all day(weather was colder today)......

[dazmond]

my numax batteries have been delivered to my girlfriends house today so i think ill swap them over this weekend,my van is also in for its first MOT on monday!wow!3 years have flown by!

[dazmond]

changed batteries today....10 min job.....a little bit awkward as its a tight space down the side of my tank,its times like this when i wish id got a van with twin sliding doors! ...put the new batteries on charge straight away and ill test them out next tuesday( my van is in the garage for its first MOT monday morning)

[NWH]

The water will be hotter straight away,it’s a head  scratch with me at the moment I’ve been charging as normal and my heater has been working better than ever.
Last couple of days it’s gone back to being smoking hot again it’s like some days the batteries are charging better than others,when I drive from job to job switch the van off and do a battery check it’s reading out 14.1 ish,before it was reading 13.1-.5 weird.

[NWH]

Even when when I’m using hot water with the heater on although the batteries have been reading a lower voltage it’s still very hot though.

[dazmond]

the only thing i didnt like on the new numax batteries is they filled the battery vents with gunk(instead of  little plastic plugs)to stop acid spilling out in transit,horrible stuff to get out of the vents...... ...got most of it out in the end.....

[dazmond]

my heater is back to its best now.....no low power warning light coming on at the end of my working day,lightening fast reeling in and the water is hotter..... cleaning my van after work this afternoon and i couldnt put my hand in front of the jets it was that hot despite 20 m off the reel and my pump on 90...my van looked like it was on fire.....

[NWH]

Lol working now is it.

[P @ F]

No his van really is on fire like the good old L5 days