biasi Riva compact HE hotwater only no Central heating..HELP

[seldom]

Hi all

I have a Biasi Riva HE, it is only giving hotwater from tap. No central heating. The following things work: Pump, air fan, flow sensor(red light), timer clock. The diverter valve pin moves in and out when hot tap is open and closed. Problem is it gives no fault codes in terms of flashing lights. My wild guess is thermistors or the flowswitch/sensor that sits on the diverter valve.

I have searched the forum for solutions and not had any luck. Any suggestions would be hugely appreciated, as i am really strung up with the finances, and if it is something simple would like to deal with it myself . thnxs

 

[Agile]

The solution has been well covered previously on this forum.

Does the red light go out when you want heating?

Its a DHW flow sensor and it sounds as if it may have jammed on.

If so can you describe EXACTLY where its fitted and what it looks like?

Tony

 

[seldom]

Thnxs for the reply Tony. The red light goes off when the flow from the hot tap stops. I believe it is also called the hall effect sensor and is clipped onto a pipe that sits central but behind the water pump. It does not come ON when the C.H is switched ON.

It seems that something is dirsupting the call for CH to the ignition. One other thing is that the CH temperature gauge at the front panel shows a rise with the DHW on, even though the CH circuit is not ON itself.

 

[Agile]

The temp gauge measures the internal flow temperature.

It should be about 55-65 on hot water and 65-80 on CH.

Please could you clarify what happens when you set the boiler for CH.

I still dont know which DHW sensor you have but thats irrelevant now as the LED is going out when DHW ceases. There were three different types fitted!

Also say EXACTLY what the timeclock display says and the position of the red switch ( if fitted ).

Tony

 

[seldom]

when the boiler is set for CH, absolutely nothing happens!!! No error lights, nothing unusual. Its like if the CH is unaware that it should come on.

The timer clock seems to work fine. It is set to manual and shows '5h in the ON' position.

The red reset switch sits centrally, and is between the panel on the left and the timer clock on the right.

thnxs

 

[dangas123]

It is likely to be an external control such as your timeclock/roomstat. use a short bit of cable to link out your roomstat at the terminals, if the boiler calls for heat its the roomstat thats faulty.

 

[seldom]

There are no external thermostats/roomstats in use.

 

[Agile]

The timer clock seems to work fine. It is set to manual and shows '5h in the ON' position.

thnxs

Doesn't your timeclock have a red slider switch? If so what position is that in?

To avoid confusion its better to use the "-" button to remove the "5" until you just have the "-" in the display.

Have you or anyone opened and exposed the PCB ? If so have you touched the connection to the timeclock?

Tony

 

[seldom]

It has red slider switch on the timer(to select between manual, timer, clock, etc), and i hve used various settings to try to get it to call for heat, to see if it has any effect.

The PCB has not been messed about with by anyone.

 

[Agile]

Timeclock slider positions are clock, progr, auto and timer!

You should select timer and press left hand button to get "on" in the display.

Whats the exact model number from boiler ???

Tony

 

[seldom]

boiler model is:m96.24sm/c2

I do get the 'ON' on the display, but like i said it does nothing. It seems something is keeping the boiler stuck in the DHW mode. It seems BIASI is a problematic brand.

 

[seldom]

I dont know if it is at all relevant, but the pump makes slight noise at start when hot tap is used. The noise dies down quite quickly and doesnt seem to affect the operation of the pump.

 

[swbjackson]

How do you know that the timeclock is working correctly? Have you used a multimeter to check the output from it? You need to check that the boiler is receiving a signal to fire before assuming a boiler fault.

 

[seldom]

How do you know that the timeclock is working correctly? Have you used a multimeter to check the output from it? You need to check that the boiler is receiving a signal to fire before assuming a boiler fault.

I haven't checked the timers output because the display function works as it should. The boiler is recieving a signal to fire for the DHW, but not for the CH. Why do u suspect the timer. Is it from experience or a hunch.

 

[seldom]

No replies for a while. Any biasi experts?