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 Plumberpro Your Own Question
Plumberpro, Plumber
Category: Plumbing
Satisfied Customers: 634
Experience:  Heating and plumbing answers. 20 years experience
Type Your Plumbing Question Here...
Plumberpro is online now

Hi I have problem with bias riva compact 24 HE. No hot wa

This answer was rated:

I have problem with bias riva compact 24 HE. No hot water
Plumberpro : Hi . Have you checked the domestic hot wTer flow switch .?
Plumberpro : As you open the hot tap , check the pin from diverted valve is coming out and making the switch. You can also take the switch off and as the tap is running press the switch in yourself to see if the boiler operates . I take it the heating works?
Plumberpro : .

Yes I checked it. pin from diverter valve switch on microswitch when call for heating but not when I open water .


Heat exchanger is clean and pump is clean to.


AAV is new. no air in the system.

Plumberpro : Hii Must be a problem with the diverted valve. I know you changed the diaphragm but you may have to change the whole thing
Plumberpro : Is your flow ok out of the hot tap
Plumberpro : If your flow is ok it has to be the diverter .Recheck the washer is seated properly.

I changed diaphragm and repair kit for diverter vales. That was first step.

Plumberpro : Is your flow ok out if hot taps ?
Plumberpro : What time are you available to chat today and I will make sure I am around?
Plumberpro : The mechanics of the diverter valve means that even if you have no power , when the water is running through the boiler the pin should come out far enough to make the switch . If this is not happening then either there is a problem with flow rate or diverter valve . We can discuss it when you are available , let me know when
Plumberpro : Hi if you are happy with your answers, could you please give a positive rating. , thanks. Toby . Or if you need further help , please continue , thank youn

Thank you for your help.

Plumberpro and other Plumbing Specialists are ready to help you