Heated grey water tank

[Fisherman]

I am considering having a heater fitted to the grey water tank on our new van. I am wondering if these heaters can be controlled manually, or do they simply come on when the temperature drops. I am concerned that they may use to much power when off EHU.

 

[r4dent]

The ones I have looked at are thermostatically controlled. To control the heater manually just involves wiring a switch into the circuit, so no problem there.

They are typically rated around 15 w (i.e. just over 1.2 amp) which means they will drain (i.e. use 50% of capacity) a 120wh battery in around 50 hours use.

Don't forget you need to think about the pipework and taps.

In my opinion you are better off leaving the drain tap open and putting a bucket under the outlet.

 

[Pudsey Bear]

Not something I would ever consider TBH.

 

[Derekoak]

I am considering having a heater fitted to the grey water tank on our new van. I am wondering if these heaters can be controlled manually, or do they simply come on when the temperature drops. I am concerned that they may use to much power when off EHU.

I assume the problem is emptying a frozen grey tank. The way to do this with minimum electricity is to warm the grey tank only before you need to empty. Or when on EHU. A switch to manually switch on an hour before emptying and the thermostat will switch off the charge when the water is at a plus temperature.
If the problem is burst pipework or tanks that is different, but a heated tank does not fully solve that.

 

[mark61]

Outside waste tank, go camping in winter. Would definitely be considering both insulated and heated waste tank. Manual control too.
I think it's a very sensible precaution.

 

[Fisherman]

Outside waste tank, go camping in winter. Would definitely be considering both insulated and heated waste tank. Manual control too.
I think it's a very sensible precaution.

Yes Mark thats the full option Rapido offer fully insulated tank and pipework, with heater.
They charge £270 with seems reasonable, but it deducts 12KG from the payload.
I reckon with an auto box my payload will be around 370KG, so every KG counts.
I will give this serious thought.

Thanks for all the replies.

 

[wildebus]

is an alternative approach, considering this is the grey tank, adding salt and so lowering the freezing point? just a thought.

 

[RichardB]

I’ve got a tank blanket that I installed on our fresh and waste.
It only comes on when temperature drops AND I have the on/off switch on. There not cheap but work well and easy to fit

 

[maingate]

If the van has Aldi heating there is usually a radiator in the bathroom (which can be Fan assisted) to remove the problem of frozen waste.

In practice it would have to be well below zero degrees for the waste to start freezing.

 

[Val54]

is an alternative approach, considering this is the grey tank, adding salt and so lowering the freezing point? just a thought.

Thinking about David's idea, what about screenwash tablets ............ cheaper if you only anticipate freezing conditions a few times a year and no payload loss

 

[exwindsurfer]

The ones I have looked at are thermostatically controlled. To control the heater manually just involves wiring a switch into the circuit, so no problem there.

They are typically rated around 15 w (i.e. just over 1.2 amp) which means they will drain (i.e. use 50% of capacity) a 120wh battery in around 50 hours use.

Don't forget you need to think about the pipework and taps.

In my opinion you are better off leaving the drain tap open and putting a bucket under the outlet.

That's all I do

 

[maingate]

As Motorhomers we have a mission to explore strange new worlds, seek out new life and new civilisations.

To boldly go where no man has gone before.

So let's not let a bit of poo get in the way of that.

Live long and prosper.

 

[trevskoda]

Two pints of antifreeze works, put it down the sink which will end up in the tank.
If leaving a house with little or no heating on put 25 ltrs in the header tank and run round the sys.

 

[wildebus]

Two pints of antifreeze works, put it down the sink which will end up in the tank.
If leaving a house with little or no heating on put 25 ltrs in the header tank and run round the sys.

Header tank? living in the middle ages there, Trev

Actually, in the house I had and did a Solar DHW setup, I fitted a Thermal Store instead of a Hot Water tank. Similar principle except instead of filling the tank with the water to use and sending the hot through the coil, you heated the tank body of water and then sent the water you were using through another coil instead of drawing it out the tank cylinder itself. That way you could put the antifreeze and rust inhibitors in the hot water system permanently - no more rusting or furred up tanks worked like a dream

 

[trevskoda]

Header tank? living in the middle ages there, Trev

Actually, in the house I had and did a Solar DHW setup, I fitted a Thermal Store instead of a Hot Water tank. Similar principle except instead of filling the tank with the water to use and sending the hot through the coil, you heated the tank body of water and then sent the water you were using through another coil instead of drawing it out the tank cylinder itself. That way you could put the antifreeze and rust inhibitors in the hot water system permanently - no more rusting or furred up tanks worked like a dream

No im talking about the central heating header tank in the loft, if a sealed sys the you drain down some and refill with a pump and then pressurize again, it will go round the rads and through the internal coil in the hot water tank when the motor valve opens, same with rads.

 

[Tim120]

Had heaters fresh/grey in my old van which worked well in as much that they stopped the water in the tanks from freezing.
Got caught in France during the Beast From The East (2018) Tanks were fine but could not drain grey due to frozen outlet pipe.
Valve was towards the end of outlet pipe with much of it exposed under van. Even if left to drain I'm sure under certain conditions it would struggle.

 

[trevskoda]

Had heaters fresh/grey in my old van which worked well in as much that they stopped the water in the tanks from freezing.
Got caught in France during the Beast From The East (2018) Tanks were fine but could not drain grey due to frozen outlet pipe.
Valve was towards the end of outlet pipe with much of it exposed under van. Even if left to drain I'm sure under certain conditions it would struggle.

You would require an electric willy warmer to sort that problem LOL.

 

[Nabsim]

You just need electric trace heating wore wrapped round tank and pipes then insulated (plus controller). It’s what we did to keep bitumen and tar fluid on the asphalt plants but obviously at a much higher temperature than you want just to stop freezing. Really need inboard tanks if you are looking at proper cold weather use thiugh

 

[Wooie1958]

Things have obviously changed for the better but back in 2005 we bought a new Adria Coral 680SL that had a 12v waste tank heater fitted as standard.

It was manual and turned on at the control panel inside the motorhome with a warning not to use it unless there was actually liquid inside the tank.

It kept the contents liquid just because we could hear it sloshing about inside but the problem was the bloody tap on the outside froze solid.

This happened on the CAMC Pembury Country Park site, the tap was underneath the side skirt so not easy to pour hot water onto, it took a lot of fannying about with two extension cables and our hairdryer plugged into the motorhome on the nearest pitch to the service point to unfreeze it

After that the damned tap then froze open so that`s how it stayed for the 18 months when had the motorhome for.

 

[rabW]

They were a standard fit on our Wildax, with on switches. I wouldn't bother, never used. They chew up battery endurance off grid, and as Wooie said the problem in real cold was outlet plumbing and drain tap freezing. Back to basics, if you're draining hot water could you not run this off somewhere at the time. eg into a collapsible container underneath.