# Defrost Fresh Water Tank Heater Wiring



## Gereshom (Jul 7, 2007)

Hello!

Has anyone had problems with their thermostatic controlled defrost fresh water tank heater?

I do not think mine has been wired in properly as does not appear to be coming on!

How long does it take to heat a 100 lt tank from when it comes on at +5 to +10 when it switches off?

Thanks in advance!  
Gereshom


----------



## spykal (May 9, 2005)

Hi Gereshom

Are you absolutely sure that you have tank heaters fitted. I now have them on my van ( an Autocruise but same applies as Autocruise is Swift) but they were fitted as a follow up to both tanks by my dealer when I discovered that they had not been fitted during manufacture or at the dealer before handover.

There does seem to have been some misunderstandings at the dealers over these heaters and this has been discussed here on MHF. see:-

http://www.motorhomefacts.com/ftopicp-860693.html#860693

So AFAIK the tank heaters are only fitted as standard to the Kon Tiki range of vans. All other models have the wiring and controls in place but the heaters and pipe insulation are an extra. It is known as a "Winter Kit" which also includes fridge winter covers. This winter kit, is it seems,  often fitted as a dealer fit, ie retrofitted at the dealer before handover if you order a new van with them.

Today was the first day that I have been able to test that the heaters now fitted to my van work.

For them to come on I have found that you need to :

1. Have them switched on at the control panel :wink:

2. The tank must be more than 25% full of water as shown on the control panel levels

3. For mine to come on the temperature of the water in the tank needed to be below 4C

I am happy to say that mine do work :lol: or at least the fresh tank one does as I have had both tanks filled above 25% waiting for a cold day and this morning was just cold enough. ( I cannot see into the grey tank so can only check that 12v DC is getting to the heater) The heaters are only rated at 30 watts so I imagine that although this may prevent the water freezing it would take several hours to raise the temperature to 10C and switch off. In fact in freezing conditions I doubt that the heater would ever manage to get the tank water up to 10C.

My fresh tank has an inspection hatch and this allowed me to check the temperatures with a probe thermometer and the operation of the heater.

If your fresh tank has an inspection hatch I suggest you take a look inside to see if you do actually have a heater fitted as the control panel light will, like mine did, light up to say "frost protect" even though there were no heaters fitted to the wiring loom.

The page at the Swift website which tells you that they are an extra on your van is here :-

http://www.swiftgroup.co.uk/motorhomes/facts-and-figures

Mike


----------



## Gereshom (Jul 7, 2007)

Thanks Mike for your reply!

I had a defrost element put in last month, which I bought from CAK. 

As far as I know it's still in the tank! CAK and Swift have been really helpful. I can only imagine it's been wired in incorrectly even though all the wiring was all there ready. I've checked the fuse and that's fine!

All the best!
Gereshom


----------



## spykal (May 9, 2005)

Gereshom said:


> Thanks Mike for your reply!
> 
> I had a defrost element put in last month, which I bought from CAK.
> 
> ...


Hi

Ah so you do have a heater :lol:

I would not start to worry too much yet as now I know that you have a heater I will explain a bit more :

I was really surprised this morning in that I had to actually lower the temperature of the water down from the 5deg C it was this morning when I first went out to the van.

I had expected the heater to come on at this temp but in fact, don't laugh I wanted to know that it was working :wink: , I had to lower the water temp by dropping 4 large deep frozen cool box blocks into the water near the heater to get it to "trip" the inbuilt thermostat , I am guessing it came on at about or just over 3 deg C then it stayed on and the water around it went up to just under 10c ...I did not wait to see if it tripped off I was happy to know that it worked OK.

If you can see the wiring, or the end of the heater where the wires attach do a check with a volt meter.

Mike


----------



## Gereshom (Jul 7, 2007)

Thanks Mike for that! 

I've thought of putting ice down there as well! So it came on at +3! I don't have a volt metre so will take the van to the garage as they left a lot of wires hanging around the tank's overflows and they could possibly short out!? I think!? I'm not an electrician!!!

Also, I'd like them to put an LCD switch so I am comforted to see when it's working!

I don't want to go back to having to empty the system before going to bed for fear of it all freezing which "nearly" happens last year!

When living in Denmark over January I had to drain the whole system! If only I had known about the double floors before buying this one!!! 

Ah well we live and learn!
Gereshom


----------



## Gereshom (Jul 7, 2007)

Just a quick note to say I've booked the van in to have the defrost element thoroughly checked but in the interim I bought a fish tank heater for £25 and this works brilliantly!

I should have thought of this from the beginning instead of paying £££ for the other expensive element!

Although, I reckon I'll have to take the fish tank heater out every time I drive the van in case it comes loose and bounces around!!

Happy motorhoming this winter!

Gereshom


----------



## Rosbotham (May 4, 2008)

...and as the tank gets empty. Aquarium heaters don't take nicely to being "run dry".


----------



## grandadbaza (Jan 3, 2008)

Does anyone any idea as to how low the temperature can go down to before the heaters dont work??

Baza


----------



## leseduts (Jun 3, 2008)

Can anyone tell me what ampage tank heaters should take out of a battery. We have just had one fitted which does not need us to do anything, so they told us. It seems to have flattened our leisure batteries in 2 days. We have taken the fuse out whilst we try to check if anything else is causing the problem.


----------



## spykal (May 9, 2005)

Hi

If the heater fitted was the CAK Tanks one it is rated at 30watts and will consume 2.5 amps at a nominal 12volts when it is heating.

Details can be found on page 20 of the PDF CAK Tank catalogue: Click here (download time may be a minute or two 12 MB) <<

We would only switch ours on at the control panel if we were on a mains hook up or were really desperate to prevent the water freezing when off a mains supply, even then I doubt it would be practical to run them ( we have 2 heaters) for long.

The heaters need to have manual switch fitted to control them.

Mike


----------

