Hi Fin,
The HydroHeat uses a 9kw diesel boiler which is integrated into your vehicle fuel tank. Robert is quite correct - the exhaust and airline are fitted through the vehicle floor - this no unsightly flues or cutouts in the roof of the vehicle.
The system comes with automatic frost protection as standard, so even with the heater switched off, if it reads 2c it will automatically kick into life and circulate hot water for 10 minutes through the circuit, including your pumps and hose reels and then back into the tank. This obviously then gives greater protection to your system overnight.
The temperate is fully adjustable with a range right upto 60c if required.
Spruce is quite correct about the various makes and models out on the market, our kit is a 9kw diesel powered boiler which uses approx 1.14 litre an hour on maximum temp.
Thanks for adding some information here. We don't get much feedback from the suppliers when it comes to diesel heaters.
I don't know how your system works, but I imagine it will be the same principle as the others. The diesel heater will heat a primary 'enclosed' water circuit containing a heat exchanger. Heated water flowing in one direction through the heat exchanger/s transfers heat to a secondary pumped line in the opposite direction from the tank which will be exit through the hose reel and up to the brush head as warm/hot water.
My question is how you derive at a 10 minute solution as an anti frost protection. Is it purely the system itself that is selected to be warmed up and protected with a little excess heat being pushed through the hose reel(?) or diverted directly back to the tank? A 10 minute start up wouldn’t do anything to raise the temperature of the water in the tank.
How many times will the system switch on and off on a cold night with freezing temperatures. Numerous short bursts of minimal heat is what Webasto advise causes the glowplug to coke up and is responsible for expensive regular servicing costs (£450.00 a time annually is a figure thrown around.)
Another issue users experience is that the systems are extremely power hungry so flat batteries are a major source of complaint as most don’t travel far or long enough to recharge their batteries.
How does your system deal with excess heat during a day’s work? If the operator stops work to talk to a customer for example or move on to the next property, the furnace will continue to heat its primary water circuit. Once the temperature reaches 74 degrees C it kicks into half heat mode. Once the temperature reaches 77 degrees C it starts its shutdown mode. After this it has to restart with more current from the battery needed. Ideally this excess heat needs to be diverted back to the tank to keep the furnace working. This helps reduce carbon build up.
In an experiment I did with my 5kw Thermo Top over Christmas I found that my heater could just manage to heat my water from 9 degrees to 35 degrees continous running. So the 9kw will produce more heat than an operator will use and hence excess heat will have to be considered, specially if only one operator is using the system.
I am a user operator, I split my van running costs by percentage into a private and business use which includes the diesel I put into the van. By drawing diesel from the vans tank, I would have no way of knowing how much diesel is being used by the van and how much is being used by the heater. If the system is running for 4 hours a day then I must assume that it’s cost me around 4 liters of fuel a day or about 80+ liters a month. The running costs of the system in diesel a month will cost me more than what the van uses, (+- 70 liters of diesel every 6 weeks).
In my opinion, anybody in my situation would require a second tank to be fitted for the sole use of the diesel heater.
From what I see, a cheap gas heater is the answer for guys like me. Its simple, easy to setup and run. Yes, a proper vent through the roof is a must IMHO, but if something goes wrong with the heater, buy another. They are on Ebay at the moment for £79.99.
