About us
Dereli Teknik is the combi boiler service that İlhan Dereli has run in Kocaeli and İzmit since 2019.
We are not a dealer for any brand; we work independently. That is why we work on all combi boiler brands and suggest the solution that suits you best. We approach every job the same way: we find the fault on site, explain what needs doing and the price before we start, and never begin without your approval. We show you the part we replaced and give a one-year guarantee on our workmanship.
Our aim is not to come once and be gone, but to be the service that looks after your boiler every year and that you can reach whenever you need us.
Why Dereli Teknik?
Two things frustrate customers most: the technician not turning up, and the price going up afterwards. We do neither.
Workmanship guarantee
If the same fault comes back within a year, we don't charge.
On-site diagnosis
We find the fault at your home and tell you what needs doing and the price before we start.
Book online
See the available days and times and choose the one that suits you. The time you choose is not given to anyone else.
Pressure keeps dropping?
When the boiler is cold, the gauge should read between 1 and 1.5 bar. If you keep having to add water, there is a leak somewhere.
We cover all of Kocaeli
From İzmit to Gebze, from Kandıra to Karamürsel: we come to your home and check your boiler on site.
We show you the replaced part
We show you the old part we removed. We don't replace parts that don't need replacing.
We arrive when we say
If we are running late, we let you know in advance.
We work cleanly
We protect the floor and leave the work area tidy when we finish.
All combi boiler brands
We are an independent service; we choose the right part together with you.
How we work
Four steps from your first message to a working boiler.
- Get in touchOn WhatsApp, in English. We ask for your boiler's brand and the problem.
- AppointmentWe agree on a day and time slot that suits you.
- On-site diagnosisWe find the fault, tell you the price and get your approval.
- Repair and handoverWe finish the job, test the boiler and explain what we did.
Message us on WhatsApp
Just tell us your boiler's brand and the problem. İlhan speaks only Turkish: write in English and he replies using a translation app. From a photo of the display or the error code we can often tell roughly what the fault is.
Phone (Turkish only): +90 535 255 88 00
Your contactİlhan Dereli (speaks Turkish)
Working hoursWeekdays 08:00–20:00
Saturday 09:00–18:00AreaAll of Kocaeli, at your home