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 Michael Your Own Question
Michael, Customer Service
Category: Appliance
Satisfied Customers: 9568
Experience:  I have been an appliance repair tech for over 30 years and will help you solve your problems.
Type Your Appliance Question Here...
Michael is online now

Hi there! My vaillant combi boiler has just stopped giving

This answer was rated:

Hi there!
My vaillant combi boiler has just stopped giving hot water, the water is luke warm at best, XXXXX XXXXX light is working and there's no error code on display! Any ideas what the problem could be? The water pressure is fine. Many thanks! Toril
Hi Toril.
Do you know if the burner actually runs now or is only the pilot light working?
Thank you
Tech Michael
Customer: replied 4 years ago.
Yes, it's running
Thanks Toril,
Once it stops let me know if the water is hot? Or just warm?
Tech Michael
Customer: replied 4 years ago.
The burner is running the whole time, but the water never gets warmer thank luke warm. Temp. On the boiler reads 66 degrees, and the flame symbol is showing. It's still not warm though.
Hi Toril,
I know the symbol is on, but please listen very carefully to it as I think the gas is not getting to the element only the pilot is on.
Let me know if you can hear the gas running.
Thank you
Tech Michael
Customer: replied 4 years ago.
You can hear that the burner is going. It is quite loud. Also the temperature rises from around 35 (underfloor heating it set to that temperature) and as high as 70 when you turn the hot tap on.

Thanks Toril,
There is whats called an aquastat in that model.
It is the temp sensor that turns the boiler on and off depending on whether the water in the tank is hot enough or not.
In this case that has failed.
This could be done by you if you have the tools and are a little handy but the best thing to do to prevent damage if you aren't experienced at this is to have a plumber or heating tech replace that for you.
However if you are handy and have the tools I will assist you and help you locate the bast place to get that part. Please let me know.
Also since this may take some time, if you will rate my service in a positive fashion thus far before you close this page, the system will allow me to schedule free follow ups with you and also ensure your question will NOT close or time out;-)
You will then be able to contact me at anytime at no additional cost until we have this fixed for you.

Thank you Toril
Tech Michael

Michael and other Appliance Specialists are ready to help you
Customer: replied 4 years ago.

Hi Michael,


We have just had a plumber around and the issue is not the Aqua stat. I realise it was hard for you to determine whether it was or not from my info online, but how does that leave me with the fee? The plumber has now been here for a while and is still trying to work out the problem. Your answers were prompt though, but didn't really solve our problem I'm afraid...

Regards Toril Simpson

Hi yes based on what you said I had to determine the likely issue.
I will let them know what you want. I am glad the problem is solved.
I only get paid for my time when a customer rates.
But I will let them know about your concern, they do take their time though so please have patience.
Thank you
Tech Michael