So you're build your own waste oil heater, and having trouble keeping it to a steady temperature. It wants to increase and decrease in temperature without you even touching anything, and sometimes even turns into a chernobyl nuclear reactor.
Why does this happen? Well simple really, as oil warms up, it flows faster, your heater heat output increases 10 fold without you knowing when the area warms up. So if you walk away from it, your heater can get out of control very quickly.
There are a few rules regarding burning oil.
#1 If the heater is inside, keep the oil outside, or via versa, this well stop the oil from heating up, therefore making it more stable, just watch out for the sunshine even that will alter the flow rate. So best situation is heater outside oil inside.
#2 Needle valves sort of work, but don't, brass wheel water valves don't. No tap we have tried works all taps will flow faster when the oil temperature increase.
This tends to occurs more with the older drip type heaters than the fan forced heaters, however oil is oil and it can be tricky stuff to control.
We have been through those terrible frightening times with the drip fed heaters, when the heater cylinder and flue turns red-white hot inside the new home and at 1200c you start to think how the ceiling doesn't catch on fire, and you know there's nothing you can do, to slow it down, apart from turning off oil flow and letting it burn out, and closing all air inlets. Using the garden hose on very fine mist sort of cools it down but more turns the shed to a sauna, don't let the water into the burning pot or the water will explode.
So our advice keep the heater outside and use hotwater to heat the home via radiators. Using a plumber to connect it up.
Even precision needle valves supply more oil when the oil warms and they clog up, so the only way is to be pump it to control the flow, and by doing this it keeps the heater at a set temperature and safe. This is the only option that works. It's like a life jacket on a boat. You don't have to wear it, but one day it just may pay. I'm still to this day amazed at the energy in waste oil.
So with our engineer's help we have designed, and built, a controlled waste oil feed, which is a timer/pump system which controls the oil flow, whether the oil gets hot or cold, it never changes the amount sent to the heater. A set measured/timed amount, and by doing this, it controls the temperature, and never goes above 3-4 degrees on what you set it at. Customers find they can leave their heaters on all day, all night, with this controller and it never alters, giving them peace of mind. These really are a must.
We use one on our heater, and it really does control it, and removes the worry out of waste oil heating. I would never run a waste oil heater without it now. You know it will not oversupply oil, therefore never overheat, and the temperature always stays the same.
With electronics being introduced, we are now able to turn the oil feed, and fan on & off via your smartphone. Which now is available to all via the wifi plugs.
Auto lighting has arrived, we have brought oil misters which operate with compressed air so will be also testing these in the next few weeks.
The engineer is building a heater as I write this, I imagine it will be a crude prototype but will work.
The complete controller wired up, with tubing and power supply, timer and pump.
Comes preset 9 second delay 1 second it pumps oil into the heater.