Ask Marcel,
the world's largest HVAC troubleshooting database.
No more 30-minute hotline calls and missing PDFs. Look up an error code — Marcel gives you the official procedure with the source in 10 seconds, not 30 minutes.
- 50,000+ fixes
- Every brand, one app
- Works even offline
Daikin, Atlantic, Viessmann, Mitsubishi… all in one app
Ask Marcel is an independent tool. All brands belong to their respective owners.
The breakdown isn’t
the problem.
The real cost? The minutes wasted searching for the right info while the customer waits and your schedule falls apart.
Time lost per breakdown
+30min
Hotline + doc search + hesitation
Hotline overloaded
Endless waiting while the customer watches.
Missing PDFs
12 folders, 47 manuals — and the right page stays hidden.
Return visit
Wrong diagnosis = second trip, margin goes up in smoke.
"The customer is watching. The hotline puts me on hold. I lose credibility in real time."
There’s a better way
Marcel suggests,
you decide.
A UI built for the field. No unnecessary fluff — just the critical data for your intervention.
AI Vision: stop typing, start scanning.
Take a photo of the nameplate, the error code, or even the flame on a stove. Marcel identifies the model and context instantly.
TARGET DETECTED
MITSUBISHI ECODAN PUHZ-W85VAA
The brain: sourced, not guessed.
Marcel doesn’t "make up" answers. It searches a database of 50,000 verified diagnostics from official manufacturer manuals.
Database search
50,000+ HVAC issues indexed
VERIFIED SOURCE:
Atlantic Alféa Extensa A.I. installer manual
— Page 34, Section 5.2
Action: leave with the fix.
Step-by-step test procedure, resistance values, and the official part reference. Close the ticket on the first visit.
REPAIR VALIDATED
Measure the flow sensor (terminal block X5, 1-2)
Expected value: 12.5 kΩ at 20°C
Official service part
NTC 10K SENSOR — REF: 567843
Every brand.
One app.
Daikin, Palazzetti, Viessmann, Mitsubishi — 50,000 structured diagnostics from manufacturer docs. Not Wikipedia.
Heat pumps
Daikin, Atlantic, Mitsubishi...
Air conditioning
Toshiba, Fujitsu, LG...
Boilers
Viessmann, Saunier Duval, Frisquet...
Stoves & pellets
Palazzetti, MCZ, ÖkoFEN...
Why Marcel, not ChatGPT?
Built for the field,
not for hype.
General-purpose AIs hallucinate. Marcel searches a verified document base and gives you the exact source: page, section, value.
- 50,000 HVAC diagnostics indexed
- Error codes for every major brand
- Structured manufacturer docs — not 400-page PDFs
- Continuous updates to technical databases
Heat pump diagnosis
"Error code 7H — what to do?"
"Flow sensor fault. Check connector X5A, measure resistance: 10kΩ at 25°C."
Source: installer manual p.67
Pellet stove
"Palazzetti A01 fault = ignition failure. Igniter at 280Ω."
Every brand
Daikin, Atlantic, Bosch, Viessmann… one interface.
One job.
Two realities.
Same breakdown, same technician, same customer. Only the tool changes.
Without Marcel
Traditional workflow
1h45
Total time
Arrive on site
Error code E7 displayed
Call manufacturer hotline...
Still waiting...
Partial answer, not sure
Searching PDFs...
Found it! (maybe)
Repair completed
With Marcel
With the AskMarcel database
20 min
Total time
Arrive on site
Error code E7 displayed
Photo → Marcel analyzes
Procedure + official source
Repair completed ✓
AskMarcel by the numbers
Average response time
Issues indexed
First-visit resolution
Per month, no commitment
Avoid one return visit = six months of subscription paid back.
Trusted by field experts.
See why tradespeople and technicians trust Marcel for their day-to-day interventions.
"At first I was skeptical about AI. But when it gave me the right sensor value for an old Atlantic heat pump in 10 seconds, I got it. It’s my expert apprentice."
Julien
Plumbing & heating contractor (69)
"I do a lot of pellet stove maintenance. Having service codes for all brands in my pocket saves a ton of time."
Marc
Service technician (33)
"Finally a tool that understands technical jargon. No more scrolling 200-page PDFs on a roof."
Thomas
Refrigeration tech (13)
"Doing flue sizing calculations live at the customer’s site is the argument that closes the sale."
Antoine
Wood/biomass installer (44)
"Marcel helped me diagnose an intermittent fault on a complex gas boiler. Huge peace of mind."
Sébastien
Heating expert (75)
"The UI is super simple, even with gloves or on a noisy site. Adopted by my whole team."
Nicolas
SME owner, HVAC (31)
"At first I was skeptical about AI. But when it gave me the right sensor value for an old Atlantic heat pump in 10 seconds, I got it. It’s my expert apprentice."
Julien
Plumbing & heating contractor (69)
"I do a lot of pellet stove maintenance. Having service codes for all brands in my pocket saves a ton of time."
Marc
Service technician (33)
"Finally a tool that understands technical jargon. No more scrolling 200-page PDFs on a roof."
Thomas
Refrigeration tech (13)
"Doing flue sizing calculations live at the customer’s site is the argument that closes the sale."
Antoine
Wood/biomass installer (44)
"Marcel helped me diagnose an intermittent fault on a complex gas boiler. Huge peace of mind."
Sébastien
Heating expert (75)
"The UI is super simple, even with gloves or on a noisy site. Adopted by my whole team."
Nicolas
SME owner, HVAC (31)
"At first I was skeptical about AI. But when it gave me the right sensor value for an old Atlantic heat pump in 10 seconds, I got it. It’s my expert apprentice."
Julien
Plumbing & heating contractor (69)
"I do a lot of pellet stove maintenance. Having service codes for all brands in my pocket saves a ton of time."
Marc
Service technician (33)
"Finally a tool that understands technical jargon. No more scrolling 200-page PDFs on a roof."
Thomas
Refrigeration tech (13)
"Doing flue sizing calculations live at the customer’s site is the argument that closes the sale."
Antoine
Wood/biomass installer (44)
"Marcel helped me diagnose an intermittent fault on a complex gas boiler. Huge peace of mind."
Sébastien
Heating expert (75)
"The UI is super simple, even with gloves or on a noisy site. Adopted by my whole team."
Nicolas
SME owner, HVAC (31)
"At first I was skeptical about AI. But when it gave me the right sensor value for an old Atlantic heat pump in 10 seconds, I got it. It’s my expert apprentice."
Julien
Plumbing & heating contractor (69)
"I do a lot of pellet stove maintenance. Having service codes for all brands in my pocket saves a ton of time."
Marc
Service technician (33)
"Finally a tool that understands technical jargon. No more scrolling 200-page PDFs on a roof."
Thomas
Refrigeration tech (13)
"Doing flue sizing calculations live at the customer’s site is the argument that closes the sale."
Antoine
Wood/biomass installer (44)
"Marcel helped me diagnose an intermittent fault on a complex gas boiler. Huge peace of mind."
Sébastien
Heating expert (75)
"The UI is super simple, even with gloves or on a noisy site. Adopted by my whole team."
Nicolas
SME owner, HVAC (31)
A pro tool priced
like a screwdriver.
One simple, transparent offer with no commitment. Built for techs who want to save time.
Pro subscription
ex VAT
/ month
No commitment • Cancel in 1 click • €295 / year
No credit card required
For teams
A “fleet” plan for your technicians & service desk.
Multi-user access, shared history, and simple rollout. Tell us how many technicians you have and we’ll propose the right setup.
Frequently asked questions
Everything you need to know about Marcel to boost your productivity in the field.
Still have questions? Contact our support team