Biasi riva compact M90e water heating problem

[FrancisBacon]

We have a Biasi Riva Compact M90E model (not sure if 24s, 28s or 32s?).

Recently the water has started to go from hot to cold when having showers as well as when turning on the taps and also one of the radiators seem to be switching itself on and off while all the others are working fine.

This happened after we went away for xmas and had the heating turned off for that period of time (a week or so) as before it was working fine. I has been like this for about 2 weeks now.

We bled the radiators that are on and also the whole system was flushed less than a year ago so not sure what is going on or whether this problem will solve itself?

We have had the boiler on max. and the heating continuously on since we got back and only switched off occasionally on the timer for about 2 hours or so. In the summer we don't have the heating on at all.

Can anyone tell me if there's anything I can do or do I need to call out an engineer?

Thanks!

 

[Agile]

The hot/cold is a blocked secondary heat exchanger.

The radiator problem is a seperate issue. Possibly a sticking pin on a TRV?

That model works better if the control knobs are NOT at max. best position is a "2 oclock".

The exact model is on a sticker on the flap ( or on the pump inside and on the data plate on the inside of the left side panel ).

Tony

 

[FrancisBacon]

Hi,
Thanks for quick reply! Found model no. 24s!

Have adjusted control knobs to "2o'clock"

As with regards to the 'blocked secondary heat exchanger' I found the following post below, however, seems a bit complicated to me so is there an easier way to deal with it or should I simply call someone out?

"the problem you have is very common,the secondary heat exchanger is partially blocked.remove the unit this takes about five mins.flush out by alternating the flow i use an old washing machine tap hose witch fits on to the heat exchanger.after flushing put the heat exchanger in the oven on medium heat this cause the metal to expand and the rest of the dirt to come away from the unit. repeat flushing can take upto half an hour .you might want to do this to the primary exchanger.before refitting top up with a cleaner/'restorer witch can be left in for a week.reflush the whole system.then fill with an inhibitor in all it takes about 2-3 hours"

With regards to the sticking pin on a TRV found the following post:

"Sticking Thermostatick Radiator Valves (TRV's) Quite often, after the summer when you start to use your heating, TRV's will stick causing radiators not to heat up. This is quite a simple job to fix; first, remove the TRV head from the body. Once done, you will see a pin in the middle of the body - it is this that sticks. Hold the tip of the pin with a pair of small pliars and push and pull it up and down a few times. This can free up the pin and allow the TRV to operate correctly again."

Actually did this with the radiators in the bathroom and that now works fine! Only problem was the pin actually fell out and almost lost it down the toilet and flooded the place! So my question is how to be make sure we don't unscrew it too much?

Again many thanks for your help! Much appreciated!

 

[Agile]

The plate HE can either be replaced or cleaned ( but not like that stupid posting ! ).

We take a ready cleaned unit for a faster change over on site. Cleaning properly needs acids and is quite messy which I dont like to have to do at a customer's home.

The posting about the radiator is fine and I think you mean that you have already sorted it out.

Tony