Frost Control

I
We have 'carried on camping' though Dec and Jan and a couple of times the Frost Contol protection gizmo has done its thing and dumped the water from the boiler as temp was below 7c. In the A/S owners manual page9-12 for Broadway it refers to an accessory that can be fitted, a Truma heating element for the FrostControl. Just wondered if anyone has fitted one of these and what the experience was? How is to gut, does it work, what was the cost?

Thanks all

There is another thread on here ( you may have already found it as your post is quite old now) that explains in detail about the frost control system.

Depending on your attitude to gadgets that try to do your thinking for you, you may like to consider changing the auto dump valve for a manual one.

Apart from anything else it seems pretty daft (to me) to have a dump valve which senses when it's cold so it can open and dump the water, then to fit it with a heater which totally negates its primary purpose . . . and effectively turns it into a manual valve!!

I have replaced ours with a manual one, which is completely idiot proof (fortunate in my case, some would say ) providing I remember to open it when frost is likely.

I don't find that difficult at all. During the cold weather season it's essential to drain down straight after a trip anyway, and one part of the process is to flip up the little yellow lever - then run the pump for a few seconds when all the water has drained.

http://www.ebay.co.uk/itm/GENUINE-Truma-Water-Heater-Safety-Drain-Valve-Push-On-Fittings-70141-02-/272537014018?hash=item3f7478cf02:g:r8YAAOSwUKxYi8ZA

Just my opinion of course, and I know others disagree - but it all depends on precisely why you want to fit the heater.

Useful reading, Thanks both.

My understanding is the dump valve should not activate if your are using the van the winter because the space/water heating will keep the temperature sufficient to prevent the drain valve from operating.

Paramedic wrote:My understanding is the dump valve should not activate if your are using the van the winter because the space/water heating will keep the temperature sufficient to prevent the drain valve from operating.

Paramedic,
You are correct - this time last year in the mountains in Spain, where the day time temperature can be deceptively pleasant in the sun, the first night we were lulled into thinking we did not require any night heat - only to be woken in the middle of the night when the dump valve opened and we discovered that the outside temperature was well below 0c. There after we left the heating on at night and set at about 12C  and had no further issues with the dump valve even though we experienced much lower temperatures. 
I think we can be comfortable and warm in bed in a modern motor-home and not realise that there has been a considerable temperature drop outside. So for that reason I am a fan of the " infamous" valve but I agree it can be a pain when it unexpectedly trips and I do think it is a tad too sensitive!. 
Liam

I have a 2016 Broadway and it has the auto dump valve of course, it also has a heater to heat the fresh water tank in case the cold water trips it.
However for the life of me, I can't understand why the tank is not insulated! To prevent the water temp dropping to ambient!
So I plan to order some insulation later in the summer and prepare for next winter!

Ray

Libraryman2 wrote:However for the life of me, I can't understand why the tank is not insulated! To prevent the water temp dropping to ambient!
So I plan to order some insulation later in the summer and prepare for next winter!
Ray

Hi Ray

There's an interesting discussion here, which is still more or less on topic.

Insulation cannot prevent the tank freezing. It can only slow the process down, and by the same laws of physics it slows down thawing by the same degree. The thermal capacity of a tank full of water will keep it from freezing solid for many hours, however cold it is, but the same can't be said for the pipework.

The comparatively tiny amounts of water in the pipes can freeze very quickly, after which it doesn't matter whether the tank is frozen solid or not - you still can't draw any water.   Much more effective therefore to insulate the pipework, and best of all to run along it some low powered heater cable or tape.

https://www.tlc-direct.co.uk/Manufacturers/Bush_Nelson/Heat_Tape/index.html

These are mains powered, which is probably quite practical since you are more likely to be on hook-up in winter, but it is obtainable as 12 volt. (I doubt if the battery would last long however.) Some of this along the pipes and under some insulation would be very effective.

That's interesting Dave, thanks.
My understanding is(correct me if I'm wrong) thatthe auto dump valve operates under two specific conditions 
1. If the ambient temp around the sensor is low enough (2degsC) 
2. Water passing through the valve that is lower than 2degs C regardless of the ambient temperature around the valve sensor!

So if the outside temperature was say -2C the the heater would be in operation and providing the water in the feed pipe had not frozen the heater would potentially prevent the dump valve from operating when the tap was run!
My understanding of decent lagging was to assume that even at -2C limited use of the heater would work to keep the water temp high enough without sucking all the life out of the batteries if not on mains (a situation I find myself in quite often)

I can quite accept that the heater elements described in the link would be useful on the feed pipe in addition to lagging..

Ray

Morning Ray

I think you are correct in every detail, but are you going to a lot of trouble (and risk, if you flatten you battery) to solve a problem that is actually created by the fancy safety valve??

If you are off hook-up and the ambient temperature is cold enough for long enough (don't forget that factor) to freeze your tank solid, you are in the clag anyway. There's no way your battery alone could cope with such extremes. Plus - would it really matter if your polypropylene fresh water tank did freeze solid?? That's not the one the auto dump valve is designed to protect.

There will be no possible risk to your hot water tank, as you will be using it all the time, using gas if not on hook-up, so the auto dump valve is totally redundant. It only really becomes useful and important if the van is not in use and you have forgotten to drain down. It then dumps the water, most importantly from the boiler, because if that freezes solid it will be very expensive.

Since there is no risk to anything that matters during the time you are using the van, it seems to me that your primary concerns are twofold.
1). Keep the water flowing by insulating and/or heating the pipework. (That could be achieved by careful use of the battery power I think.)
2). Replace the auto dump valve with a manual one, which won't over-react and leave you with no water, and rely on your common sense to open it and drain down when you leave the van unoccupied.

The basic point at issue is - the auto dump valve was designed primarily to protect the boiler when the van is unoccupied in case the owners forget to drain down. It's not really of much use when living in the van, since the boiler will be in use and therefore at no risk.

That's how I see it anyway.

Hi Dave, thanks for helping me to understand the function of the valve a little better!
If I can clarify my viewpoint; I really aren't worried about the tank freezing, I'm guessing that I'm being a little too anal about this valve and my tank water temperature!
E.g a couple of w/e's ago, the temperature was -1 C or so....
I worried somewhat about the valve dumping my water...(probably unnecessarily)..so I ran the heater all night...and as per my expectations; the battery suffered a little...
Now; as far as I'm aware the heater has a thermal cut off so it does not just run all night but clearly; it's not ideal when no hook up is available!
I really need time to assess the behaviour of this dump valve and find out when it's prudent to use the heater and when it's not needed!
To be fair, I don't think there's enough info for me about its parameters of use but many thanks for lending me your ear and your view.

Ray

Gromit wrote:Morning Ray

I think you are correct in every detail, but are you going to a lot of trouble (and risk, if you flatten you battery) to solve a problem that is actually created by the fancy safety valve??

If you are off hook-up and the ambient temperature is cold enough for long enough (don't forget that factor) to freeze your tank solid, you are in the clag anyway. There's no way your battery alone could cope with such extremes. Plus - would it really matter if your polypropylene fresh water tank did freeze solid?? That's not the one the auto dump valve is designed to protect.

There will be no possible risk to your hot water tank, as you will be using it all the time, using gas if not on hook-up, so the auto dump valve is totally redundant. It only really becomes useful and important if the van is not in use and you have forgotten to drain down. It then dumps the water, most importantly from the boiler, because if that freezes solid it will be very expensive.

Since there is no risk to anything that matters during the time you are using the van, it seems to me that your primary concerns are twofold.
1). Keep the water flowing by insulating and/or heating the pipework. (That could be achieved by careful use of the battery power I think.)
2). Replace the auto dump valve with a manual one, which won't over-react and leave you with no water, and rely on your common sense to open it and drain down when you leave the van unoccupied.

The basic point at issue is - the auto dump valve was designed primarily to protect the boiler when the van is unoccupied in case the owners forget to drain down. It's not really of much use when living in the van, since the boiler will be in use and therefore at no risk.

That's how I see it anyway.

Hi Gromit and congratulations on a most comprehensive synopsis extolling the virtues for the dump valve. Me thinks that you have convinced yourself to reinstall it on your van. Harrah....you have seen the light!

Just the opposite Paramedic.

The main point I tried to make (and obviously failed ) is that the auto dump valve is designed to protect the boiler, which obviously doesn't need protecting when the van is occupied. Therefore it's of little use to Ray.

If I understood his comments correctly, he's trying to avoid the unwanted dumping of water when he's using the van. Simple fix - fit a manual dump valve and take back control of his life!

We are currently in Spain where overnight the temp dropped to minus 4 degrees and the frost control emptied our water tank. We cant fit a manual drain at this stage so wondering how best to deal with this situation. We do a lot of wild camping so we are often without  EHU.

There is a tank heater but I'm not sure if it would flatten the battery if left switched on when there's no electricity. 

Also Liam mentioned leaving the heater on at night set at 12 degrees but I'm not sure how do do this. We are on our first big trip in this van and still working everything out so any advice appreciated. It's a 2012  Broadway by the way.

Thanks

Assuming you're not on mains electricity, then do not use the tank heater because it will indeed rapidly flatten the leisure battery.

Assuming you have gas, use your (probably Truma) gas heater to keep the van snug. Set the theromostat at a suitable temperature. At night, turn it down to a lower temperature - that should stop the dump valve from activating.  Ensure that the dump valve is not smothered in paraphanalia, so that the warm air inside the van can keep the dump valve warm enough to avoid its opening.

Beware of drain on leisure battery, however. A few days of constant heating will discharge it, unless topped up by solar panel or a run or mains.

Cymro

Hi Joeirish,
Yes, I endorse all that has been said by Cymro. 
In particular the issue with regard to the potential battery drain when the heating is on - as the fan will be functioning, all be it very slowly, all of the time and will therefore be a net drain on the battery. But you should be OK if you get solar top-up during the day. 
I am not familiar with your particular heating set-up but assuming its a Truma, you should be able to leave it on its lowest setting such that the thermostat (ours is digital, hence 12 deg - yours may be a dial) will fire up the boiler when the temperature drops. The residual boiler heat will circulate around the immediate area to it and therefore prevent the auto dump valve (which is located near by) from opening. The manual states that the valve will auto open at 3deg C but some people have found it to operate at higher temps - it depends on how sensitive your valve is.
Well that is my theory and it has worked for me!
Have a good trip.

joeirish wrote:We are currently in Spain where overnight the temp dropped to minus 4 degrees and the frost control emptied our water tank. We cant fit a manual drain at this stage so wondering how best to deal with this situation. We do a lot of wild camping so we are often without  EHU.

Hi Joe

I think you can fit one, very easily - assuming you can get one. All you need do is undo two screws and release the push fit connectors on each side, then pull up the auto dump valve. Its drain pipe will be sealed into the hole in the floor, so just pull until it lets go.

You then need one of these. They are not cheap, but you may find one locally as it's a standard Truma part, or perhaps get one sent out to you. It's only a ten minute job and saves all the faff with loss of water.



https://www.amazon.co.uk/John-Guest-Safety-Drain-Valve/dp/B00H5Q63NU/ref=sr_1_5?ie=UTF8&qid=1546508245&sr=8-5&keywords=motorhome++water+drain+valve

If you do get rid of the auto dump valve you should have a note to self (not sure where I would post it) reminding you to self open and drain the boiler in future!

Liam wrote:If you do get rid of the auto dump valve you should have a note to self (not sure where I would post it) reminding you to self open and drain the boiler in future!

I've just left a note in mine reminding me that my valve is open after draining down yesterday, so I don't feel a fool when I next fill and see the water draining out straight away. I have a manual valve.

I came home on Tuesday after the festivities and felt shattered, I unfortunately left the van full of water and the taps on!

I went into the van in the morning and the pump was running....probably most of the night after the dump valve let the water out!!
I refilled the tank a bit and tried the pump...luckily it still works o.k..
I changed my van after this original post so I never fitted a manual device.

Ray

Gromit wrote:

joeirish wrote:We are currently in Spain where overnight the temp dropped to minus 4 degrees and the frost control emptied our water tank. We cant fit a manual drain at this stage so wondering how best to deal with this situation. We do a lot of wild camping so we are often without  EHU.

Hi Joe

I think you can fit one, very easily - assuming you can get one. All you need do is undo two screws and release the push fit connectors on each side, then pull up the auto dump valve. Its drain pipe will be sealed into the hole in the floor, so just pull until it lets go.

You then need one of these. They are not cheap, but you may find one locally as it's a standard Truma part, or perhaps get one sent out to you. It's only a ten minute job and saves all the faff with loss of water.



https://www.amazon.co.uk/John-Guest-Safety-Drain-Valve/dp/B00H5Q63NU/ref=sr_1_5?ie=UTF8&qid=1546508245&sr=8-5&keywords=motorhome++water+drain+valve

Thanks but not a job I want to do while away without all my tools and only a little Spanish. Moved to warmer climes now in any case. But it looks like I didn't loose all my fresh water, just what was in the hot water cylinder. I'll leave heating on next time!

Thanks for the replies. The information is very helpful. We only tend to stay two nights at most before moving on and I think using the engine and having a solar panel should be good enogh if we have to leave the heater on low overnight. The water tank heater seems to use about 1.2 amps. Not sure how quickly that would flatten my battery. But should be ok for three or four hours before it causes a problem but maybe others would be able to advise. The Sargent panel tells me this.

“I've just left a note in mine reminding me that my valve is open after draining down yesterday, so I don't feel a fool when I next fill and see the water draining out straight away. I have a manual valve”

Took the van out for it’s second outing last week, the site owner told me where the water tap was but I informed him I had filled up before leaving home. Switched on the power only to find a fresh water low warning.
Didn’t realise the frost valve had tripped and all my water had gone in transit (can this actually happen or have I missed something?).
I do hope he was not watching when I had to make several trips to the tap that I said I didn’t need!

Dbvwt wrote:Didn’t realise the frost valve had tripped and all my water had gone in transit (can this actually happen or have I missed something?).

I've not experienced it David, but someone asked about this some time ago, probably last winter.

Several people had experienced water loss in transit. Perhaps someone will remember more accurately than me what the consensus of opinion was. 

If temperature is low enough, I'm sure it will dump the water. It may have opened before you actually got under way and therefore before the temp inside the van had risen sufficiently.