Budgie823 Posted October 27, 2019 Share Posted October 27, 2019 Hi all, I have a Autosleeper Warwick XL fitted with the Truma automatic frost valve. I have tried manually draining the boiler in preparation for the winter but the boiler fails to drain. I am confident that the valve is open and have proved this by operating the water pump at which point the water flows freely through the boiler and out through the drain point. As soon as I stop the pump the water stops flowing. I have also confirmed that there is water in the boiler. It may be that I am missing something simple but can think of no logical reason for the failure. Any help will be much appreciated. Many thanks Link to comment Share on other sites More sharing options...
Keithl Posted October 27, 2019 Share Posted October 27, 2019 Have you opened the taps and shower to allow air in? Keith. Link to comment Share on other sites More sharing options...
Budgie823 Posted October 27, 2019 Author Share Posted October 27, 2019 Tried this Keith but no joy. Thanks anyway. Link to comment Share on other sites More sharing options...
BruceM Posted October 27, 2019 Share Posted October 27, 2019 Are you sure that you’ve also emptied the drinking water tank? I don’t see how operating the pump would pump water through the boiler (and out the boiler frost drain) unless the drinking water tank still contained water. Link to comment Share on other sites More sharing options...
colin Posted October 27, 2019 Share Posted October 27, 2019 BruceM - 2019-10-27 10:47 AM Are you sure that you’ve also emptied the drinking water tank? I don’t see how operating the pump would pump water through the boiler (and out the boiler frost drain) unless the drinking water tank still contained water. Along similar lines, it could be the Truma is empty, but you are just pumping fresh water into it. Link to comment Share on other sites More sharing options...
Budgie823 Posted October 27, 2019 Author Share Posted October 27, 2019 I have tried with both the water tank empty and also full. I understand there is a non return valve between the tank and the boiler so the contents of the boiler should empty even when the tank contains water. I am confident the boiler is full as I am getting a full flow through the taps with the pump runnng and the frost valve closed. If the boiler is empty I don't think I would get this flow. My other thought now is that the blue button on the frost valve pops out but only about 5mm and I am wondering if it is not fully opening? Link to comment Share on other sites More sharing options...
colin Posted October 27, 2019 Share Posted October 27, 2019 Where is the pump on your set up? With our van the pump is a submersible in the fresh water tank, with no water in the fresh tank no water comes from hot taps even if the Truma is full. p.s. Thinking about it, I've only ever known the pump to be on fresh water side be it in or out of tank, all the ones I know of rely on pumping water into the Truma, so it may well be that Truma is empty, but you still have water in the fresh water system, be it water still in the tank or residual water in the pipes. Link to comment Share on other sites More sharing options...
Budgie823 Posted October 27, 2019 Author Share Posted October 27, 2019 The pump is submersible and I can see your logic Coilin. However I am confident the boiler is full because I am getting the free flowing water through the taps and the boiler is located between the tank and the taps. In the past when I have emptied the boiler I have had to re-prime it by operating the pump with the taps open to exhaust the air from the system. I am not having to do this now, hence the thought that the boiler and system are full of water. Link to comment Share on other sites More sharing options...
Will86 Posted October 27, 2019 Share Posted October 27, 2019 Budgie823 - 2019-10-27 11:11 AM I am confident the boiler is full as I am getting a full flow through the taps with the pump running and the frost valve closed. If the boiler is empty I don't think I would get this flowi? A full flow you say ... where's it coming from ... if that particular source has water in it then the boiler will always be topped up, I'm puzzled why you don't empty everything, I see no reason why any water should remain, winters can be severe. Link to comment Share on other sites More sharing options...
BruceM Posted October 27, 2019 Share Posted October 27, 2019 Budgie823 - 2019-10-27 11:11 AM . . . I understand there is a non return valve between the tank and the boiler so the contents of the boiler should empty even when the tank contains water. I think that you’ll find that the non-return valve is there to prevent water flowing back into the main water tank from the pipes/taps/boiler but not the other way around so I suspect that you’d not be able to empty the boiler without emptying the main water tank. Link to comment Share on other sites More sharing options...
BruceM Posted October 27, 2019 Share Posted October 27, 2019 Budgie823 - 2019-10-27 11:11 AM My other thought now is that the blue button on the frost valve pops out but only about 5mm and I am wondering if it is not fully opening? That’s an interesting point, so are you saying that when you operate the frost valve you do not see any water draining from the drain point underneath the van? If so, then I suspect the issue lies with then frost stat operation or a blockage in the drain pipe, or the boiler is indeed empty and the water emitted when the pump is turned on is coming from the main water tank. Link to comment Share on other sites More sharing options...
Budgie823 Posted October 27, 2019 Author Share Posted October 27, 2019 I think you are right about the non return valve Bruce. This allows water to enter the boiler from the water tank but not the other way i.e. From the boiler to the tank. I have once again emptied the tank but the boiler, as a result of this non return valve remains full. To my knowledge the only way to empty the boiler is via the frost drain valve and this cannot be happening as a bucket placed under the van beneath the drain point remains dry. I think it is likely that the valve is not opening fully so think I shall probably take the van into the dealer. I appreciate the help and advice from all those who have responded and many thanks for your thoughts. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted October 27, 2019 Share Posted October 27, 2019 When a Truma safety/drain valve is opened, water in the boiler should begin to drain through the valve. Although opening a hot-water outlet will speed up the draining process, the boiler should still empty satisfactorily as air should enter the boiler through the ‘breather elbow’ that’s near the top of the boiler. That is what the breather is there for, otherwise (once any pressure in the boiler has fallen to zero) the boiler is likely to stop draining. The non-return valve that prevents water draining back through a submersible pump into the main water tank is irrelevant, as is whether that tank is empty or full. If the boiler has water in it and the breather and the safety/drain valve are both functioning properly, when the safety/drain valve is opened the boiler should drain completely. Link to comment Share on other sites More sharing options...
Budgie823 Posted October 28, 2019 Author Share Posted October 28, 2019 Many thanks for your clear explanation Derek. I have now successfully drained it after firstly checking and confirming no blockages or restrictions on any inlet ducting or vents. I then operated the frost valve several more times until I finally got a good flow. I can only assume the valve had been sticking closed but I'll probably never know for sure. One thing it highlights is the need to place a bucket under the outside drain point to confirm that drainage has been successful. Thanks again to all. Link to comment Share on other sites More sharing options...
tonyishuk Posted October 29, 2019 Share Posted October 29, 2019 A. Couple of passing thoughts ! Some people say leave the taps open so that any remaining water will drain out , others have suggested closing the taps because insects like to hibernate in dark and mysterious places. When refilling the system you may experience leaks and drips from the drains. When closing the taps they do not seal properly, either a bit of muck , or seal is slightly displaced. Repeated opening and closing the taps to allow flow , generally sorts this out. I ( if I remember) try the taps every three months, to keep the seals and tap mechanisms from seizure a nod supple. This seems to have worked over the years, rather than once a year use, and resulting problems. Rgds Link to comment Share on other sites More sharing options...
Budgie823 Posted October 29, 2019 Author Share Posted October 29, 2019 Many thanks for the useful info Tony. Cheers Link to comment Share on other sites More sharing options...
Derek Uzzell Posted October 30, 2019 Share Posted October 30, 2019 There is a good deal of on-line advice about draining a motorhome’s water system. After water has been drained, taps should always be left in their fully-open position and, if a tap is mixer-type, the tap's operating control should be centralised so that both its hot and cold inlets are open. I don’t recall it being mentioned before that insects might enter an open tap and that this could subsequently be problematical, but if a tap is left closed there is a very real risk water will remain within the tap and, if that water freezes, that the tap will be irreparably damaged. It is sometimes suggested that external drain taps (for fresh-water and waste-water tanks) be closed to prevent insects entering the tanks, and (where practicable) it makes sense to protect the external cowl of a gas heater as discussed here https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/101-Reasons-To-Cover-Your-Truma-Outlet-/50706/ Basic draining of a motorhome’s water system relies on gravity and, although gravity should adequately remove water from taps and heating appliance ‘boilers’, getting water out of cassette toilets (the toilet itself not the cassette) will need to be considered and - after gravity has done its best, water will still be left in water hoses. Potable antifreeze is marketed to pump into the water system (though I don’t know how many UK motorcaravanners do this) or residual water from hoses can be blown out with compressed air using either a commercial product https://keepfloeing.com/shop/motorhome/ or a DIY method. Link to comment Share on other sites More sharing options...
thebishbus Posted October 30, 2019 Share Posted October 30, 2019 When draining for the winter, I open all drain valves and taps. When it is all drained I rock the van back & forward in first & reverse to shake out any pooled water. Then pour a drop of car screenwash (contains Antifreeze) down the sinks to protect the water traps (one froze and cracked one year before I did this). I then leave the valves and taps open. Brian B. Link to comment Share on other sites More sharing options...
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