laimeduck Posted November 23, 2010 Share Posted November 23, 2010 This is my first post & I'm an electrical dunderhead so go easy with me please. I have searched the Forum can't find an answer. I have a Benimar Perseo 710 CCX (2005), since February this year. Previously I had caravans. In the recent cold snap the automatic drain valve in the Truma boiler opened & drained all the water from the main tank. Not a problem in itself, but I had been working in the van & had left the control panel on. The water pump cut in & drained the two 110 AmpHr Leisure batteries & the motor battery. (The leisure batteries are under the bench seat behind the passenger seat) Fortunately, I realised the problem the following morning & connected to the mains and the charger has now recharged all batteries. (There is no swith to select batteries) (I had a recent similar problem in France when the Control panel indicated that the Electric waste water valve had stuck open. This also drained both sets of batteries even with the mains charger working, and I had to jump start the van. As we have a manual waste water tap I was somewhat confused! A Phone call to the dealer resulted in me scrabbling under the van where I eventually found the redundant waste water valve control box and taped up the offending microswitch which resolved the problem) I was told that the Motor battery is totally separate from the Leisure batteries, but this is obviously not the case? Now I have searched the Benimar Owners Club forum & “Faulty Split Charge Relay” would seem a likely candidate to examine. What am I looking for & where can I find this relay? (I also intend to research “Battery Manager”, but the relay is favourite at present.) Incidentally, the episode raises another question? How do I stop the water draining out through the Truma boiler when the temperature drops? Do I have to keep the boiler on continuously or the mains water heater on continuously? The boiler is in a compartment off the rear garage. I intend to use the van throughout the winter, usually with an electric hook up, but occasionally on the Autoroute we will stop with no hook up. The Benimar users manual is basic (chocolate teapot!) Any help wwill be received with thanks Jeremy Link to comment Share on other sites More sharing options...
Randonneur Posted November 23, 2010 Share Posted November 23, 2010 laimeduck - 2010-11-23 7:09 PM I intend to use the van throughout the winter, usually with an electric hook up, but occasionally on the Autoroute we will stop with no hook up. The Benimar users manual is basic (chocolate teapot!) Any help wwill be received with thanks Jeremy Welcome to the Forum. Can I just say it is not a good idea to stop overnight on Aires/Service Stations on Autoroutes. They are not safe. You are better off coming off the autoroute and finding the first Village and stop there and then get back on the Autoroute the following day if you must. We very rarely use the pay Autoroutes and we set our SatNav to not use Toll roads. I am sure other Members will be on here to give you advice regarding your electrical problems. Link to comment Share on other sites More sharing options...
Brian Kirby Posted November 23, 2010 Share Posted November 23, 2010 The auto drain down valve on the Truma will open at low temperatures to protect the boiler from freezing. VERY expensive if it happens. If you are using the van, and so have the heating on, the Truma, and its enclosure will be warm. If you are using hot water, so much the better. I am assuming a Truma Combi type heater with an electric water heater element. If so, it is quite a good idea to leave that on during cold nights, assuming you have paid for hook-up. It is thermostatically controlled, and reasonably low wattage, so not an abuse of the supply, and a boiler full of hot water nicely keeps the chill off the van while maintaining the boiler way above the trigger temperature for the drain valve. Short breaks, like meal breaks, should not see the heater temperature fall to critical levels. Stops off hook-up are a bit more tricky, the best remedy if it is really cold will be to leave the heater on a low setting at night, or select water heating at its lowest setting. If you think the temperatures will not go low enough to freeze the boiler, put a clothes peg on the drain valve, so that it can't open! You just have to remember you've done it.When not using the van, drain it down, and open the boiler valve to ensure all water is out. If it is cold enough water in an unheated van will, eventually, freeze, and will almost invariably damage something. Link to comment Share on other sites More sharing options...
terryW Posted November 23, 2010 Share Posted November 23, 2010 Brian Kirby - 2010-11-23 7:12 PM put a clothes peg on the drain valve, so that it can't open! You just have to remember you've done it.. These drains are normally close to the boiler and a full tank of hot water works to keep them from opening when in residence. If you switch the hot water heating off overnight but leave the blown air heating on at its lowest setting this acts as a fail-safe. These should open at about +3 degrees and close around 7 or 8, not sure of the exact temperature. This can make it difficult to fill when it's a bit cold and to overcome this problem a 12 Volt heating element is available that fits to the drain valve. The handbook for my last van gave the part number for this but I found that a heat pad or hot water bottle worked just as well. When the tank is full of water you can then switch on the boiler, heating the water and your ready to go. Terry Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 24, 2010 Share Posted November 24, 2010 terryW - 2010-11-23 9:33 PM ...These should open at about +3 degrees and close around 7 or 8, not sure of the exact temperature. This can make it difficult to fill when it's a bit cold and to overcome this problem a 12 Volt heating element is available that fits to the drain valve... Terry Terry's advice seems to relate to the current Truma "Combi" range of combination air/water heaters, which were not marketed in 2005 when Jeremy's Benimar was built. Jeremy's heater will almost certainly be an earlier C-Series appliance. The electrically-operated 'safety' drain-valve used with C-Series appliances is electrically connected to the heater and opens when the air temperature at the drain-valve drops below 4°C. The drain-valve cannot then be closed until the air temperature at the drain-valve EITHER exceeds 8° OR the heater is switched on and 'summer' (water-heating only) or 'winter' (air-heating) mode is selected. The "FrostControl"safety drain-valve used with current "Combi" heaters is not electrically operated and is not electrically connected to the heater itself. It opens when the air temperature at the drain-valve drops below 3°C and cannot then be closed until the air temperature at the drain-valve exceeds 7°C. As the Combi's drain-valve is not electrically connected to the heater, switching on the heater does not override the latter restriction. As Terry mentions, this restriction presents potential problems in cold weather, so Truma offers as an accessory a heating element (part no. 70070-01) that is inserted into the FrostControl valve and is electrically connected to the Combi heating system. This element heats the FrostControl to approx. 10°C when the Combi is switched on. This means that the boiler can be filled irrespective of the air temperature at the drain-valve. While it's easy to imagine scenarios where Truma 'anti-frost' drain-valves can protect your combination heater from expensive damage, most of the time they are a bloody nuisance. I remember once asking whether any forum member could confirm - hand on heart - that a Truma anti-frost valve had actually saved their bacon. There were no replies. The simplest solution for living with a C-Series electrically-operated drain-valve is to treat it as if it were manually operated. Basically, this means jamming the valve in the closed position (clothes-peg, elastic band, etc.) when the motorhome is being used and, when the motorhome is out of use in cold weather, opening the valve to drain down the heater. As no other leisure-vehicle water heaters have this type of 'automatic' drain-valve and owners of those vehicles (or most of them!) seem quite capable of remembering to drain the heaters/boilers hen necessary, I'm sure it can't be that hard. (Although it's pretty easy to jam shut a C-Series drain-valve, the Combi valve presents more of a challenge.) Link to comment Share on other sites More sharing options...
747 Posted November 24, 2010 Share Posted November 24, 2010 Somewhere in your van there will be a switch that cuts off the 12 volt supply. This should be a failsafe way to stop your pump running dry. I have a suspicion that you may need a new pump in the near future as they do not like running dry. Follow the advice regarding draining and then cut the power. Vans vary in setup but somebody should be able to tell you where this switch is. It is handy to know if you are laying up the van for long periods. Be aware that it may cut off the power to your alarm. Probably not but best to check. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 24, 2010 Share Posted November 24, 2010 747 - 2010-11-24 12:41 PM Somewhere in your van there will be a switch that cuts off the 12 volt supply. This should be a failsafe way to stop your pump running dry. I have a suspicion that you may need a new pump in the near future as they do not like running dry. Follow the advice regarding draining and then cut the power. Vans vary in setup but somebody should be able to tell you where this switch is. It is handy to know if you are laying up the van for long periods. Be aware that it may cut off the power to your alarm. Probably not but best to check. Switching off the motorhome's main habitation 12V power-supply to protect the water-pump means that everything fed through that switch (lights, heater, etc.) will cease to function. This is fine when the motorhome is out of use, not so great when you are 'living' in it. Most (all?) 'vans should have on their control-panel an On/Off switch dedicated to the water-pump and best practice (particularly where a pressure-sensitive pump is involved) is always to move that switch to its Off position when it can be anticipated that the water-pump won't be needed for a while (eg. when the motorhome is being driven, when the vehicle is left unattended, etc.) Even when the 12V supply to the water-pump is switched off, if the pump is the submerged type there's every chance that, should the Truma drain-valve open, the motorhome's main fresh-water reservoir will be emptied by siphonic action as well as the boiler part of the Truma heater. Obviously, if the motorhome is to be out of use for an extended period in cold weather, it should be properly drained down and everything electrical that isn't considered essential (eg. an alarm system) should be switched off. Link to comment Share on other sites More sharing options...
laimeduck Posted November 24, 2010 Author Share Posted November 24, 2010 Thanks to all for your replies with reference to the Truma drain valve. I still need to sort the Motor Battery discharge problem though? Brian/Terry/Derek • I have looked up the detail and it is indeed a C Series (a Trumatic C3402 with 230Volt hot water heating collar.) It would seem that the modus operandii is to fire up the hot air heating to get the ambient temperature around the safety drain valve to above 8 degrees C, then shut the valve, after which the tank can be filled with water. Then use the 230Volt hot water heater or gas hot water heater to keep the whole lot hot! Or go out & buy a clothes peg! - and another coloured ribbon for the wing mirror. ( When a ribbon is on the mirror it tells me to do something before I drive off – different colours for different functions eg mains cable, rear steadies etc etc – I know my limitations!) Randonneur • I have been caravanning & now motorhoming it for 30 years in France & have always used Service Stations & Aires on AutoRoutes with never a problem? Thanks for the warning though. Derek & 747 • Yes of course - the 12 Volt switch is on the control panel – I simply forgot to switch it off as I was working in the van. • Yes I figured that I ought to keep the water pump switch turned off most of the time. PS For most of the last 25 years I have taken a caravan out to the French Alps in February to go skiing. Temperatures regularly dip below -15 dgrees C. No problems with the caravans as we used gallon water containers & left a convection heater on permanently. Seems it may be a bit more complicated with the Benimar Motorhome though! Only one way to find out? Jeremy Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 24, 2010 Share Posted November 24, 2010 laimeduck - 2010-11-24 6:22 PM ...I have looked up the detail and it is indeed a C Series (a Trumatic C3402 with 230Volt hot water heating collar.) It would seem that the modus operandii is to fire up the hot air heating to get the ambient temperature around the safety drain valve to above 8 degrees C, then shut the valve, after which the tank can be filled with water. Then use the 230Volt hot water heater or gas hot water heater to keep the whole lot hot! Or go out & buy a clothes peg!... I suggest you go for the clothes-peg. When filling your C-3402 with water in cold weather, there should be no need to run the air-heating to get the air near the drain-valve to above 8 degrees C. Just switching on the heater and putting it into 'summer' water-heating mode (via gas not via the 230V heating-collar) should allow the drain-valve to be shut. If you use the blown-air heating approach, by the time the air near the drain-valve gets hot enough to allow the valve to be shut, the insides of the heater are likely to be well hot. And then you are going to fill the heater's reservoir with water that, most probably, will be frigid. A C-3402 water reservoir cost around £300 in 2002 when my cracked one needed to be replaced. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 25, 2010 Share Posted November 25, 2010 Jeremy, Returning to your motor-battery discharge problem… I’ve looked at the Benimar forum and found the thread you refer to. The norm for Continental European-built motorhomes is to use a ‘coupler/separator’ rather than the ‘split-charge relay’ employed on many UK motorcaravans. With a coupler/separator, when the motorhome’s engine is started the alternator’s charge is initially directed only to the motor battery. This situation continues until the motor-battery’s charge-state reaches a predetermined level, at which point the leisure-battery is ‘coupled’ in parallel with the motor-battery and begins to be charged by the alternator. When the motorhome’s engine is stopped, the coupler/separator disconnects the leisure-battery from the motor-battery to ensure that, if either of the batteries is flattened, the other remains unaffected. It’s commonplace to find a split-charge relay installed separately (often within the vehicle’s engine compartment), whereas a coupler/separator may well be located within a ‘black box’ carrying other relays, fuses, etc. On my Hobby this ‘box’ is beneath the right-hand cab seat, but I’ve no idea where Benimar might have installed such a component on your Perseo. Anyway, I agree with your diagnosis that your problem is relay-related. The “Battery Master” mentioned on the Benimar forum is designed to pass a low amperage current from the leisure-battery to the motor-battery to keep the latter topped up charge-wise. It’s a useful add-on when the motorhome’s electrical system does not include the facility for the vehicle’s on-board battery-charger to charge the motor-battery. From what you’ve said, your Perseo’s battery-charger automatically charges all your batteries simultaneously when the motorhome is on electric hook-up (EHU). This capability reduces the attraction of Battery Master, though it might be useful if you were storing the vehicle off EHU, when your 220Ah of leisure-batteries could maintain the motor-battery’s charge state for a considerable time. However, it sounds like you keep your Perseo at home where you have easy access to a 230V power source. Motorcaravan converters’ owners’ manuals are often a mish-mash of short extracts from the original instruction documents relating to the major ‘leisure’ appliances installed within the motorhome. In such instances, it’s better to try to obtain the original and much more complete documentation for those appliances. You can download Operating and Installation Instructions for your Truma C-3402 heater via www.truma.com and (depending on the makes/models involved) you may also be able to download original manuals for your Perseo’s fridge, toilet, water-pump and some of its electrical components (battery-charger, control-panel, etc.) if you are prepared to spend some time GOOGLE-ing. Where original manuals aren’t available on-line, most manufacturers will send you them if you e-mail them and ask nicely. Link to comment Share on other sites More sharing options...
laimeduck Posted November 25, 2010 Author Share Posted November 25, 2010 Derek Once again thanks for this. I have already downloaded the manuals for equipment. (The manual that came with the Perseo is not for our model and most of the fittings and appliances are different ) I have also made a contact at the Benimar factory in Spain. I will ask nicely about a "coupler/separator" and see if they can help locate that or a split charge relay. You are right that I keep the Perseo at home and will now keep her hooked up. Thanks once again - I'll keep you informed of progress! Link to comment Share on other sites More sharing options...
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