Slump heating and refrigeration technology


After 15 years in the field of refrigeration engineering, Marco Slump started up his own independent business Slump heating and refrigeration technology in Appingedam (NL) last year.

His company has F-gas certification from the Dutch testing facility Kiwa and his work mainly involves heat pumps, air conditioning systems and thermal solar plants.

He is a huge fan of Testo measuring instruments and has up to now used the digital manifold testo 557 in combination with various Testo Smart Probes.

Logo Slump

testo 557s thrills Marco Slump

Marco was one of the first engineers in the Netherlands to put the new testo 557s through its paces in a practical environment. He was already hugely satisfied with the previous generation so he was extremely curious to see whether we could make things even better.

"I have not yet managed to use all the functions but my first impression is that it is fantastic! A real improvement in terms of ergonomics and it also has an appealing visual appearance. I am pleased to see that the vacuum sensor port at the top of the testo 557 has been discontinued for the testo 557s: This was actually extremely sensitive to moisture and dirt. The accompanying case also has a clever design, which is mindful of the Testo Smart Probes and hoses."

"I have just had the opportunity to use the new meter with some heat pumps."

"The Bluetooth functionality works much better between the phone and testo 557s than it did with the old testo 557. The new App is much quicker at generating reports, which represents an enormous improvement. I left it outside for while at low temperatures to see whether it would still function properly; it was actually -7 on the roof. A few hours later the meter was also at approximately -5 degrees. There were no problems whatsoever in relation to functioning or the formation of condensation on the display. With my old testo 557, I did actually have issues with condensation on the display in winter."

Portrait Marco Slump

"In short, my first quick impression is very positive; a lovely new manifold set which you will not regret purchasing as a refrigeration engineer. I don’t think any other make can match it."

Marco Slump, owner of the heating and refigeration technology company Slump, Appingedam (NL)

testo 557s on Marco’s van
We’re happy to report that Marco is such a big fan of the testo 557s that he’s put a photo of it on the back of his company van.

"I can see that the manifold has a new design with attention given to providing lots of improvements. I find the various measurement programmes for the types of work on an installation very useful. I have been working in the refrigeration industry for 15 years, and previously you had to do certain things yourself, with waiting times to check for leaks etc. There are now programmes available in the software which you can use to generate a report automatically. I don’t actually want to go back to how it was previously. It is also very easy to familiarise yourself with the intuitive App."

"In short, my first quick impression is very positive; a lovely new manifold set which you will not regret purchasing as a refrigeration engineer. I don’t think any other make can match it."

Application digital manifold testo 557s

All results at a glance. In your hand.

The testo 557s digital manifold with Bluetooth and a 4-way valve block features a large graphic display, a compact, robust housing, guided measurement menus and the testo Smart App. Top-quality measurement technology, a high degree of reliability and smart functions for quick, easy measurements and documentation make the testo 557s manifold a reliable partner for your commissioning, servicing and maintenance of refrigeration and air conditioning systems and heat pumps.

  • Large graphic display for easy evaluation of measurement results
  • Stored programs guide you through the measurement and make it possible to automatically determine key system parameters such as superheating, pressure drop test or evacuation
  • Straightforward to handle, with maximum flexibility for your application: Bluetooth probes for temperature, pressure and humidity connect to the manifold automatically
  • testo Smart App: Create digital documentation straight away on site, set your own favourites, always have the latest refrigerants thanks to automatic updates
  • Continuously high performance in all conditions: You can depend on this manifold from Testo – it combines proven Testo quality with excellent robustness
  • testo 557s Smart Vacuum Kit testo 557s smart digital manifold with Bluetooth and 4-way valve block, 1 x testo 552i wireless vacuum probe (Bluetooth), 2 x testo 115i wireless clamp temperature probes (Bluetooth, NTC)
  • Kit also available with 4-hose filling set (testo 557s Smart Vacuum Kit with filling hoses)
Digital manifold testo 557s

testo 557s Smart Vacuum Kit

testo 557s Smart Vacuum Kit
with filling hoses

New digital manifolds from Testo