Are all truck mount carpet cleaning machines the same?
No. The biggest difference is where the heat comes from. Most truck mounts recover heat as a by-product of the engine already driving the vacuum and the pump, so those three jobs compete. A separately fired heater does not compete, so the temperature holds when the trigger stays down.
Written by Bency John, owner-operator at ApexClean — who does the cleaning as well as the writing.
What does “truck mount” actually tell you?
“Truck mount” describes where the machine sits. It doesn’t describe what it does.
“Truck mount” says where the machine sits, not what it does
A truck mount is a truck mount. If the van has one, you’re getting the good version of carpet cleaning, and the differences between machines are details for the trade to argue about.
What reaches your carpet is where the heat comes from
The phrase covers wildly different machines. And the difference that actually reaches your carpet isn’t the badge on the side — it’s where the heat comes from.
One engine, three jobs competing — vacuum, pressure, heat
A carpet cleaning system has three jobs to do at once: pull a vacuum, push water at pressure, and heat that water. The question is what’s powering each one.
In most truck mounts, one engine does all three. The vacuum blower and the pump are driven directly, and the heat is recovered from that same engine — from the exhaust and the cooling system — through a heat exchanger. It’s efficient engineering, and it works.
But it means the heat is a by-product. It exists because the engine was already running for other reasons. And that creates a relationship most people never hear about: the three jobs are competing. Ask for more vacuum and more flow at the same time, and the heat available per litre of water falls, because you’re now pushing more water past the same recovered energy. Systems like this need layers of control to manage that trade — and they are generally set to a safe, conservative level so the balance never tips somewhere awkward mid-job.
A separately fired heater doesn’t play that game. The water is heated by its own burner, with its own fuel, doing one job. Vacuum and pressure can do whatever the job needs and the heat isn’t fighting them for a share, because there’s nothing to share.
That is why two machines quoting a similar temperature can behave completely differently in your lounge. One number is a peak that has to be protected. The other is a working temperature that holds while the trigger is down. The specification sheet cannot tell you which one you’re getting.
There’s a second difference worth knowing, and it’s the one most often blurred: the pump and the heater are separate machines. A system can pair a modest pump with a powerful heater, or the reverse, and the brochure will quote whichever number reads best. Four-figure pressure figures usually belong to hard-surface work — tile and grout genuinely want them — and have nothing to do with carpet, where a higher pressure figure is not a better clean.
Half your lounge cleaned cooler than the other half
- A temperature that fades mid-job means the second half of your lounge was cleaned cooler than the first half, and nothing about it looked different at the time.
- Big rooms and commercial carpet cleaning are where recovered heat is asked the most and shows the strain soonest.
- Stop-start jobs — moving furniture, working around people — give a recovered-heat system time to catch up, which is why a small job can look fine while a large one disappoints.
- A brochure number is a peak. What you actually want to know is what it holds, and almost nobody publishes that.
Ask where the heat comes from — the engine, or its own burner
- Is your heat from the engine, or does the machine have its own burner? There is no wrong answer, but the answer tells you a lot about how the day will go.
- Does the temperature hold on a big job, or does it need a break?
- Where is your temperature measured — at the machine, or at the wand?
- What’s the machine, and what’s it rated at? Ask what they actually run, not what it could do.
- Is the machine set up for carpet, or for hard floors as well?
Ours is a dedicated 120,000 BTU burner, not engine by-product
Our water is heated by a Little Giant 3HTHP — a 120,000 BTU LPG-fired heater from the company that patented the first instantaneous gas water heater in 1921. It is a separate, dedicated unit: it isn’t recovering warmth from an engine that’s busy elsewhere, so it isn’t in competition with the vacuum or the pump. Heat doesn’t sag when the trigger stays down.
Pressure is a separate machine, and worth separating because the two get sold as one: the water is pushed by our van-mounted hybrid electric system, up to 600 PSI. On carpet we work well inside that.
We publish that number as 120°C at the machine, because that is the one place a temperature can honestly be measured — and what reaches your carpet is always less.
At the carpet, on a synthetic pile, we’re working to somewhere around 70–90°C — and we’ll say plainly where that range comes from: years of doing this, not a laboratory.
On wool it is far lower, and on olefin lower again. Wool loses its natural lanolin and can shrink and distort if it’s run too hot, and olefin has such a low melting point that high truck-mount heat will mat it down or weld the fibres together. So there is no single correct temperature, and anyone who quotes you one number for every carpet in the country is telling you they don’t change it. Fibre first, then the setting.
That is the whole thing in one line: plenty of machines can’t reach these numbers. Ours can, and most of the job is deciding not to.
Which is the part a spec sheet will never tell you — so ask. And if you’d rather skip the sales call entirely, our price is online, to the dollar, in 90 seconds. No NZ carpet cleaner we’ve audited offers that, which tells you something about how the quote usually works.