Having a good caravan heating system will be an essential part of an enjoyable touring experience.
Even if you’re staying at one of the best caravan parks in the summer months, there can still be a chill in the air at times, prompting you to turn to your van’s heating. Here, I’m answering some of the common questions you may have about the heating systems we find in our caravans.
You can also take a look at our best heater for a caravan guide, where we share our top picks on the market to keep you warm.
1 Are caravan heating systems effective?
Properly maintained caravan heating systems in a modern, well-insulated tourer will be very effective indeed.
It will not only heat the interior space quickly – typically reaching your target temperature in around 20-60 minutes – it will also be able to maintain that level of warmth very efficiently.
UK caravans are frequently tested in industrial-size cold chambers, which can generate temperatures below -20°C.
So a modern tourer could keep you very warm, cosy and comfortable, even in those conditions. These days, they really are four-season leisure vehicles.
2 Are caravans fitted with separate heaters for hot water and space heating?
Many modern caravan heating systems will heat both the interior space and the water in a single combi unit.
Clever engineering means that these combination heaters are small enough to fit underneath a settee in the living area, and are quiet, reliable and efficient.
That said, you can actually purchase separate space and water heaters, although these are far more commonly found in campervans and smaller motorhomes.
3 How does caravan space heating work?
Caravan ‘central heating’ systems generally work in one of two ways: blown air or wet (radiator) heating.
The simplest of these systems are the blown-air designs, which are basically large fan heaters that distribute warm air throughout the caravan interior, using a combination of flexible ducting and adjustable vents.
The other option is wet heating, which is like domestic central heating, with a boiler, and radiators distributing the heat.
4 What do I need to know about blown-air heating?
The two biggest manufacturers in this sector in the UK are Truma and Whale. Truma makes combination heaters that warm the caravan interior and heat your hot water, while Whale manufactures separate water and space heaters, many of which can be mounted underneath your caravan’s floor. The two Whale units are monitored and adjusted from a single control panel.
To heat the caravan’s interior, air is warmed using either gas or electricity, or a combination of the two. The gas is burned in a central combustion chamber, and the heat from it passes into a series of heat-exchanger fins.
Ambient-temperature air is drawn in by a fan and passes over these fins, heating up as it does so. This can be boosted by electric heating elements in the airflow, or you can use electric heating alone.
Once it has been warmed, the hot air is blown out of the heater along ducting that takes it all around the caravan.
The heating system is thermostatically controlled. It will cut off once the target temperature in the van has been reached, and kick in again to boost the temperature as and when necessary.
5 So how is wet radiator heating different?
The boiler part of the wet system is not dissimilar, but it uses heating fluid instead of air to distribute the heat around the caravan, just like many home central heating systems.
This fluid circulates around the system, passing over the heat-exchanger fins. On each circuit, as the temperature is boosted, the heat gradually builds up.
At strategic points around the circuit, this heated fluid passes through a heated towel rail, radiator units hidden behind the furniture, panel radiators and sometimes an underfloor heating system. At each of these points, it radiates the heat to dry towels or warm the air.
Alde wet boilers also vary in that they need a reservoir for their heating fluid. This container is usually located at the back of a wardrobe, and normally contains a magenta-coloured liquid.
This is a G13 glycol antifreeze solution and is the fluid that is heated and circulated through the pipes. These antifreeze properties ensure that it doesn’t have to be drained down in very cold weather, although it does need to be checked annually for strength/dilution, and changed every five years.
This fluid also contains inhibitors that slow the degradation of the pipes and internal surfaces in your caravan heating system. Changing your heating fluid is generally a job for the professionals, and will cost from £150 to £250, as it is quite involved.
However, experienced DIYers could attempt this job themselves, which brings the cost down to around £30 for the fluids, although it’s advisable to buy a pump, too. A basic pump costs from £10 and can be found on eBay. Video tutorials on YouTube demonstrate the process.
6 Which is best, blown-air or a wet radiator system?
Well, how long is a piece of string? Which of these systems would be best for you depends very much on your requirements, caravan and family sizes, and of course, budget. Alde wet heating is generally considered the more high-end and luxurious option, and can be found in almost all luxury caravans.
Of course, maintenance costs are higher over the lifetime of a van, and there are more elements to go wrong. There seems to be a consensus that Alde heating can deliver a more uniform heat throughout a caravan, and its operation is silent. Another benefit is that Alde’s Compact 3030 boiler features a two-zone system – so, for example, you could have your washroom warmer for towel drying, and your bedroom cooler for sleeping.
Caravanners in the Truma and Whale blown-air camp will rightly claim that it warms a van more quickly, and deny they get cold spots in their tourer.
I have to say, I’ve never had an issue with cold spots in a caravan, with either type of heating. In fact, I would say both systems are capable of making a caravan uncomfortably hot within an hour!
I generally need to have a window open to let in cool air, especially when sleeping.
One slight downside with blown-air caravan heating systems can be the noise of the fan, especially with older models. This is very much a background sound, but it can feel a little intrusive when you’re sleeping in the front lounge bed and the boiler’s directly beneath your head. Light sleepers might want to consider this.
Because most caravan heaters tend to be combination boilers, their water-heating capabilities should also be part of your decision-making process. This is generally expressed in litres and is the capacity of their hot-water cylinder.
Bear in mind that this capacity is boosted when it is mixed with cold water on leaving the boiler (to make it a safe temperature). As an example, Alde’s 10-litre cylinder capacity is boosted to 17 litres with the addition of cold water, and might be enhanced by the settings of the user in the shower, to, I’d estimate, 20-25 litres. The boiler’s energy output should also be considered.
7 How much output am I going to need?
This depends on the size of your caravan and the number of its occupants. if you’re in a 4 berth caravan, assuming that the tourer is larger, and especially if everyone showers in the caravan (rather than at the site facilities), I’d always go for a 6kW system, such as Alde’s Compact 3030 (3.3-6.4kW), or Truma’s Combi 6 (which can be used at 2kW, 4kW or 6kW).
In a caravan for couples, or if you exclusively use campsite facilities, a 4kW heater should suffice for both space and water heating. Of course, the systems can be set to several outputs to suit your particular heating needs.
8 Does the gas I use make any difference to the heating output?
Yes. Propane contains slightly less energy than butane. For example, the Alde 3030 generates 3.3kW on Setting One with propane, and 5.5kW on Setting Two.
Meanwhile, with butane, it generates 3.8kW and 6.4kW respectively.
9 Which brands of caravan heaters are the best?
In the UK caravan market, there really isn’t a great deal of choice. Typically, you’ll find that blown-air systems are made by Truma and Whale, while wet radiator systems come from Alde. All offer space and water heating, and all are time-proven products.
10 Does caravan heating need much in the way of maintenance?
In general, modern caravan heating systems are very reliable, and I’ve heard of very few problems over the years. Occasionally, I’ve been told about the electronics failing and a new circuit board being needed, but a heater that is checked and maintained annually should give many years of reliable service.
Alde heating systems should have their fluid checked annually and replaced every three to five years, while all water heaters (not Alde radiator heating) should be drained down before putting your van into winter storage, to prevent the risk of potential damage from freezing.
If your Alde system makes any noise, it might need bleeding. You can find the instructions online, but first ensure the pump speed is set to 2-3 on the side of the unit, because your technician might have altered it for testing.
As part of the tourer’s annual service, caravan technicians will test the exhaust gases emitted from your boiler.
When gas is burning efficiently, the flame is blue. Where the flame isn’t visible, they’ll carry out a flue-gas analysis test with a specialised meter.
This measures the emissions and will highlight if there are any problems with the gas burning fully and whether the burner requires maintenance.
Likewise, they will check that the flue is clean, the gas pressure remains consistent, the electric and gas systems have both been correctly earthed, and the orange (10 years) or black (five years) gas feed pipes are still within their recommended lifespans before replacement.
11 Are caravan heaters expensive to service?
Caravan heating systems are serviced as part of the tourer’s annual maintenance regime, which will typically cost from £140 to £300, depending on the size and complexity of your tourer, and whether you use a dealership for the servicing, or go to an independent mobile technician instead.
12 What about underfloor caravan heating systems?
Let’s start by clarifying that ‘underfloor heating’ (UFH) has two rather different meanings in leisure vehicles.
First, several manufacturers, including Whale, produce compact heating units that mount on the underside of a caravan, motorhome or campervan, literally under the floor, on the exterior of the vehicle. This frees up room inside the caravan and any noise is kept outside. The units are protected in robust, waterproof casings.
UFH as we know it in domestic terms also exists in some luxury caravans, having been championed by Alde. These systems warm the floor and the heat rises gently throughout the
van. As Alde heating guru Neil Marsden explains: “Alde’s UFH is hydronic, like the rest of the system. The UFH pipe is 12mm PEX-AL-PEX with aluminium spreader plates and it’s plumbed into the main heating circuit, containing the antifreeze fluid. Alde tests have found it’s not possible to heat a caravan solely with UFH, because heat loss is far greater than in a building. The UFH would have to run at too high a temperature for comfort or health. So in a van, UFH is only ever supplemental to the main heat source.
It’s a great luxury, though, being able to walk comfortably barefoot on your van floor, regardless of the weather. This also affects your body’s temperature regulation. With comfortable feet, the rest of your body doesn’t want as much heat, so you can set the thermostat lower, saving energy.”
Electric UFH can be retrofitted to caravans by the experienced DIYer or a caravan technician.
Ebeco Foil 48V is sold by the metre in various widths, and at a thickness of just 0.3mm, it can be laid under caravan vinyl flooring. The low-voltage system requires a transformer and is fused, with built-in overheat protection.
13 Are caravan heating systems safe to use while you’re sleeping?
A well-maintained caravan is perfectly safe to sleep in with the heating running. On campsite electric hook-up, the cautious might prefer to only use electric heating, and we would, of course, always recommend fitting a carbon monoxide (CO) detector/alarm in every caravan.
14 Which power supply is more economical, gas or electricity?
When on hook-up, I’d typically use the heating on an electric setting. While campsite electricity has increased in price in recent years, bottled gas has seen greater inflation and my most recent 13kg Calor refill cost more than £50.
15 Will my heating work off-grid?
Off-grid caravanners rely on gas for almost all of their energy needs, including heating, cooking and refrigeration. Experienced wild campers tend to have two gas bottles on board, and top up their leisure battery with solar power, although this 12V power isn’t sufficient to run the heating.
Given the cost of bottled gas, frequent off-gridders should consider Safefill gas bottles or the Gaslow self-fill system, which you top up yourself with LPG at Autogas petrol stations. This costs around a third of the price of Calor gas.
16 What’s the ideal temperature for the thermostat in a caravan?
Setting a caravan thermostat between 18°C and 21°C creates a comfortable environment for most. For those who feel the cold, a heated throw is an excellent investment if you’re using hook-up. We should all be using energy sensibly – keep the thermostat as low as possible, and swap for extra jumpers and blankets whenever you can.
17 There are draughty air vents in the caravan floor – can I block them?
These vents are gas drop-outs, designed to let heavier-than-air gas flow out of the caravan in the event of a gas leak. They will also allow CO to escape, so they should never be blocked up.
It makes good sense to invest in a CO detector for your van, and if you smell gas on entering your tourer, exit immediately, leaving the door open.
18 Can I use an additional heater in my awning?
Technically you can – unless you’re on a campsite where these are banned. However, we’d strongly recommend not heating your awning (see: the best caravan awnings), for environmental reasons – so it might be worth investing in some thermal vests!
19 Are caravan heating systems easy to control?
The latest heating systems are extremely easy and intuitive to control, typically via an LCD control panel close to the door. Using buttons or touchscreens, you can choose between water and space heating, then select the power source and the level of output in kW. On some Alde 3030 heaters, you can set two zone temperatures; on blown-air systems, you can select the fan speed.
20 Why does the electric sometimes cut out when I switch on the caravan heating?
The most probable cause is that you’ve exceeded the electricity supply of the hook-up post. This is displayed in amps, and is usually 10-16A in the UK, but may be as low as 6A on the Continent.
With a 230V supply, a 10A supply gives you 2300W (2.3kW) to play with, while a 6A supply only allows you up to 1380W. So if you turn on your electric heating at 3kW on either supply, it will exceed the load and the hook-up circuit-breaker should trip. Bear in mind, too, that your fridge might be using 125W, your lights 60W and your caravan TV another 60W. It all adds up.
21 Can I control my heating when I’m away from the caravan?
Modern vans have integrated systems and appliances that can be controlled via a smartphone app – in theory, wherever you are!
The heating, air conditioning, lighting, battery level and security can often be monitored and controlled from afar using systems such as Truma’s iNet X, Whale’s iVan and Alde’s Smart Control.
The verdict on caravan heating systems
Caravan heating systems have become extremely efficient and sophisticated in recent years, as manufacturers have embraced the use of new materials, new technologies and the digital revolution. Choose wisely, set the thermostat sensibly, and you will come back to a warm caravan and a hot shower whenever you tour!
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