How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Andrew Smith Your Own Question
Andrew Smith
Andrew Smith, Home Appliance Technician
Category: Appliance
Satisfied Customers: 3629
Experience:  Gas cooker specialist
46681511
Type Your Appliance Question Here...
Andrew Smith is online now

Hello. I have a vailant ecotec pro28 combination boiler. The

Resolved Question:

Hello.
I have a vailant ecotec pro28 combination boiler.
The boiler works absolutely fine when demands for heating., All controls/screen display ok.
When a demand for hot water is called for, the boiler operates exactly as it should, the boiler fires and modulates to full power, but drops back almost straight away. Boiler still carries on running but at a low gas rate, so water is only luke warm.
When removing the NTC sensor from the hot water heat excahange, the boiler works correctly.
The NTC sensor has been replaced, but still the same.
Please any advice what the error maybe?
Doug
Submitted: 3 years ago.
Category: Appliance
Expert:  Andrew Smith replied 3 years ago.
***** ***** :

If the sensor has been replaced then you are almost there

***** ***** :

If it is reading correctly then the plate heat exchanger must be up to temperature

***** ***** :

The problem must be in the heat transfer between the boiler circulating water and the cold water

***** ***** :

It looks like your plate heat exchanger is scaled up internally, you should get this cleaned to solve your problem

Customer:

Hello.

Customer:

Hello, thanks for the reply. Would it be easier/wiser to replace the heat exchanger ?

***** ***** : no, they are made from stainless steel, just need to clean it in a bucket of commercial descaler
Andrew Smith and other Appliance Specialists are ready to help you