Caravan advice: Your technical questions answered

There's not much that our DIY expert Lee Davey doesn't know about caravans – he's our go-to guy for any niggling problems or technical issues.

Lee has toured all over the world in his caravan. Each month in Caravan magazine, Lee is on hand to share his advice on your queries and questions, however major or minor.

You can buy digital issues of Caravan magazine, including back issues which contain previous Q&A articles with Lee, from our online store here.
 

Water pump blowing the fuses in a caravan

Q. When I came to set up my eight-year-old Bailey Olympus caravan after the extended winter break I found that, when switching on my water pump in a full cassette of water, it keeps on blowing the fuses! Have you any suggestions as to why this is happening and what I should do?

A. The most likely cause is a stuck impeller inside the water pump – the bit that sits inside the Aquaroll. From memory, your Olympus will have a Whale system fitted and they usually respond well to a screwdriver rotating/freeing the impeller. 

You may have to remove a cover/casing for impeller access. Obviously, it's best to remove the unit from the caravan first. If this doesn’t work, and it's this unit that's at fault, it'll be time to buy a new one.

Caravan noseweight knowledge

Q. I know my car has a 100kg limit on the tow hitch. However, what is the ideal noseweight to tow with? I know it must be a positive number, but I don’t want to use the maximum 100kg.

A. The ideal noseweight should be between 5% and 7% of your caravan’s MTPLM, or maximum laden weight. Using the MTPLM figure, the noseweight would be between 70kg and 98kg. Personally, I tend to set my noseweight towards the 7% figure if my car and towbar will allow it.

Now you know how much your nose weight should be, it’s time to measure it. With your caravan loaded, place a noseweight gauge under the hitch and raise the jockey wheel until the noseweight gauge is taking all the downward weight of the hitch. If you haven’t got a noseweight gauge, bathroom scales and a piece of sturdy wood cut to length can make an ideal substitute.

If the noseweight is too heavy, move any floor-mounted luggage towards the rear and check again. Do the reverse if the noseweight is too light. Due to a possible pendulum effect, avoid moving heavy items more than 2ft (60cm) either side of the axle. If this isn’t possible, time spent rearranging heavier items is time well spent and will make for an enjoyable and safer tow. Enjoy your next adventure!

Awnings size for a Lunar Clubman caravan

Q. I’ve just bought a Lunar Clubman 475-2 and need to know the awning rail size – it isn’t very clear to me.

A. The awning chart suggests the length of awning you require is 895cm. This usually translates into a ‘900’, although sizing can differ between manufacturers. As awnings can be expensive, it’s worth double-checking the measurement before purchasing. It’s a simple process, but make sure the caravan is level before you begin. From ground level directly below one end of the awning channel, measure along the complete awning rail, with the final measurement being at ground level below the other end.

Retrofitting a barn door

Q. Can you tell me if it possible to retrofit a barn door from another Swift model to my 2017 Swift Freestyle S4 EB? For us, it really is the only thing missing from what is a really fantastic and well-designed caravan.

A. It isn’t something I have done before, so I spoke to the team at KTG Caravans. It has swapped several caravan doors, with some being from different manufacturers and painted to match. It tell me that fitting a new door is certainly possible if the frame size is the same. It keeps several doors in stock and can be reached on 01782 636306 or email [email protected]
 

Can a VW Passat tow my caravan?

Q. Could you please advise on whether a VW Passat 1,600cc will be able to tow my Sterling Eccles Topaz? Will it be legal and safe? We have been caravanners for over 30 years but am now confused with this vehicle.  

A. Looking at online data for your Volkswagen Passat, the kerbweight is 1,459kg and the manufacturer’s towing limit is 1,500kg. Both major UK caravanning clubs suggest an 85% kerbweight match, but the National Caravan Council state that a 100% match is possible for experienced caravanners. Your caravan is a 94% match, which is legal and should be a relatively easy tow given your 30 years of towing experience. See outandaboutlive.co.uk/caravans/towmatch for more info.
 

Caravan heating system issues

Q. I can’t get my heating to work on electric – I’m new to this so could really do with some help!

A. You don’t mention which heating system you have, so I’ll give a broad overview which should apply to all heating systems with a 240V option. The first, and simplest, thing to check is the fuse/RCD board to make sure everything is in order. If power is reaching the heater but it still refuses to work, it could be the heating element. Some elements can be costly so it may be worth asking a caravan engineer if they can diagnosis the problem before any work is carried out.

Water pressure problems

Q. I have recently purchased a 2007 Compass Corona 362. I have a problem with the pressure of the water and also the fact that there is a lag in delivery pressure – it dribbles then slowly builds pressure. Water takes ages to fill the Trumastore and with much gurgling and spitting.

Does the system have some pressure-switching device? I have had many caravans and, in all, the water came into the caravan and then into some form of pressure sensor which switched on and off the pump. In the Compass it appears to come in and straight to the Trumastore and to the cold taps. There are two valves – the usual lift and flip drain valve (yellow) and another which is an ‘inline’ or ‘across’ style valve which appears to drain the Trumastore. Am I missing something?

A. As you say, the problem does suggest a faulty pressure switch, so I contacted the helpful folks at Truma Technical Support for clarification. It agrees with our diagnosis and says that it may be in the form of a surge damper, or it may be a switch from another manufacturer. Poor water pressure could also be the result of faulty non-return valves within the pipework. For a ‘hands on’ diagnosis, it may be worth contacting your local caravan dealer or servicing agent.

Got a query?
Our expert team is happy to answer your questions, whether they relate to touring or towing, DIY or disasters. Whatever it is that's been causing you trouble, we're on hand to help.

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