Biasi 24 S and 24 SR

[grill]

Hi guys,

Was called out to do an annual service on the boilers mentioned before and ran into some funny stuff

24 S - The green on light was flashing on off on off but the boiler seemed to be working fine. Checked the (crap) manual but there was no fault finding section. anyone know what this signifys??

24 SR - This is bizarre. when i got the boiler the system pressure was 0.3 bar so i automatically seeked out the fill loop to top it up. Found what i thought was the fill loop under the boiler and turned it on. No response. Decided to check back and see if there was a stop valve back up teh line but the pipe went into the wall and literally disappeared.

Head scratching begun. Then i happened to glance up and found a secong separate filling loop on the cold water inlet pipe and it was sitting at 0.3 bar. Climbed up and again turned it on but nothing. Pressure actually dropped a bit!!! I phoned up the owner and he said that tehre had been problems since day one with the water pressure in the house.

The boiler wont run at the minute which i assume is down to low pressure. Want to get the pressure right befor ei start any further fault finding. Im going back tommorrow. What should i be looking for???

Thanks in advance

Grill

 

[matt83]

Biasi have seperate service manuel which can be downloaded from there web site.... But the fault finding section is cr@p!!!

 

[Agile]

24 S - The green on light was flashing on off on off but the boiler seemed to be working fine. Checked the (rubbish) manual but there was no fault finding section. anyone know what this signifys??

I can only assume that that was an M90-24S ???

The green light on that is meant to flash !!!

The manuals for the Biasi boilers are some of the best you will find.

A good boiler engineer finds faults by basic principles and doen not have to look at fault finding guides, they are for the users.

So did you measure the mains pressure at the second property?

Tony

 

[Rob]

[quote="grill]

The boiler wont run at the minute which i assume is down to low pressure. Want to get the pressure right befor ei start any further fault finding. Im going back tommorrow. What should i be looking for???
[/quote]

Is there water present and is it connected to the mains? Whats the mains pressure like at the kitchen tap? If you dont have a guage try using you hand to stop the flow. 0.3 bar is similar to what you would get from a tank so this is a possibility!

 

[Agile]

The original 24S will still operate with only 0.3 Bar. Not going to get much DHW flow rate though.

However he should be doing simple diagnostic things like seeing if the flow switch is being activated.

Tony

 

[Gasguru]

AFAIK no Biasi's are fitted with pressure switches so they will run with zero on the gauge. When they are really low (and a bit empty) the differential sense will stop the burner (although the pump will cook).

Considering the abuse I've seen these boilers go through they are surprisingly robust compared to many other makes. Manuals (if you need them) are amongst the best. Check their site.

 

[matt83]

Am i the only one who wants (or needs) a nice easy to follow fault finding flow chart....... But having said that i spend 98% of my time doing installs.

 

[Dan Robinson]

I like to have one there for readings, etc., but an electrical flow chart is more useful. As Tony says, once your in front of it the logic should be fairly obvious (unless its a Sine ).

Thermister readings and specific idiosyncrasies are nice to have in paper form in front of you; but the manufacturer seldom bothers to print the really useful ones (Potterton Suprima Gas Valve resistances anyone?).



I have most manuals to hand on a laptop, but I have to mentally justify the battery time...

 

[Rob]

(Potterton Suprima Gas Valve resistances anyone?).

About 2k each. Ones slightly more than the other.

 

[Dan Robinson]

1600 I thought, but it has been a while... My point was that it was a vital bit of information that you needed to correctly diagnose the PCB of vavle at fault.

Even their techgimps didn't always feel the need to tell you as it meant another one or two PCB sales.

 

[grill]

Hi guys,

Cheers for all the replies.

Tony i do know exactly how to fault find without any manual but i just want to have the basic right before i start so i do get lead up the garden path.

Water tap pressure at the sink was low but will measure properly today.

Cheers for the advice on the boiler running on zero pressure. Sort of takes that issue out of the equation.

And cheers for teh flashing light on the 24 S. All good.

I havent worked on biasis before so wasnt sure. As i state in every thread. Im new to this game and still finding my feet!!!

Grill

 

[ChrisR]

(Potterton Suprima Gas Valve resistances anyone?).
1.3k Ohms and 2.8k Ohms !

 

[bobthebender]

Biasi boiler manuals are excellent and the boilers themselves are the best £ for £ boiler on the market.....says i

Grill.....a short pulse flashing light every 4 seconds means the boiler is in stand by condition.
Very fast pulses (4 per second) means faulty boiler.
As per a previous biasi post...The schraeder valve is at the top (not bottom) and the zilmet vessel has to be pressurised to 1bar.
The flue restrictors are not made of metal and there are no fins to break off. (tony ?)

 

[Agile]

Bob is only talking about the M90 or M96 models !

Grill doesn't seem to know the difference! Clue: model is on the data on the front flap !

Tony

 

[grill]

Guys,

Thanks for your help. Im a little further forward on my quest for boiler knowledge. Obviously have a lot further to go (eh tony!!).

By the way it was a M90-24S. I dont understand your last comment??

Im away to try and sort the pressure out on this other one. Suck it and see.

Thanks again.

Grill