Biasi boiler problem please help!

[thurwood]

Hi Everyone
Please can someone help I have a Biasi 24s combi boiler that I have spent a lot of money on but still not fixed and the recommended Bisasi engineer in the South West is a joke and doesn't show up for his appointments twice. The boiler works perfectly when running just hot water. When you put the central heating on it runs until it gets too hot then shuts down the boiler when it cools down you can press the re-set button and it works for a few minutes again then once again shuts down when the temperature gets hot. There is no room wall thermostat. This is a small flat but getting cold and very annoying! The last plumber was unable to fix the problem and just left in a huff and said get a new boiler Biasi boilers are cheap rubbish!! I can't afford a new boiler but this must be a simple common problem? Is there anyone that can advise?

 

[mehran]

what you have described would be a classic ntc fault on a biasi 24S boiler. a competent RGI would be easily be able to confirm and replace the ntcs.

 

[thurwood]

what you have described would be a classic ntc fault on a biasi 24S boiler. a competent RGI would be easily be able to confirm and replace the ntcs.

The last plumber said it was not the thermister which he changed Is the ntc a temperature probe and is there 2 of these? We have been told it is the by-pass valve?? Thanks

 

[mehran]

mmm... even if the bypass was leaking by i can't imagine the boiler would heat up to the point of overheating. it would see it was getting hot and shut down the boiler before overheating.

could be wrong though

 

[thurwood]

mmm... even if the bypass was leaking by i can't imagine the boiler would heat up to the point of overheating. it would see it was getting hot and shut down the boiler before overheating.

could be wrong though

So would you go with changing the ntc probes are there 2 of these? Is the thermister one of these ntc thingys There doesn't seem to be a competent engineer in Swindon! The Biasi engineer is in Andover and didn't show for 2 appointments!

 

[mehran]

I carry sensors for most boiler makes...so yes I would change the 2 of them (would check the resistances first). I have had quite a few over the years with the same sounding fault.

their are some other less likely things the could do it but from what you have said ntc's are most likely

 

[thurwood]

I carry sensors for most boiler makes...so yes I would change the 2 of them (would check the resistances first). I have had quite a few over the years with the same sounding fault.

their are some other less likely things the could do it but from what you have said ntc's are most likely

So can you confirm wether a thermister is one of these ntc's so I don't buy the same one again as one was checked and found to be OK Thanks

 

[kevplumb]

So can you confirm wether a thermister is one of these ntc's

yes

its a wait for it




"Negative Temprature Coefficient thermistor"

copied and pasted from the CC

 

[mehran]

the biasi NTC looks like this:

there is two of them, one on the flow and one on the return.

 

[thurwood]

the biasi NTC looks like this:

there is two of them, one on the flow and one on the return.

Hi Do any of you live or work in the Swindon area? I have no idea which NTC was changed but it did look like the picture you posted Do they look identical? The bloke did try changing a "thermister" but with a used one from another Biasi Thanks for your help Tamara

 

[thurwood]

the biasi NTC looks like this:

there is two of them, one on the flow and one on the return.

Hi Do any of you live or work in the Swindon area? I have no idea which NTC was changed but it did look like the picture you posted Do they look identical? The bloke did try changing a "thermister" but with a used one from another Biasi Thanks for your help Tamara

Also would the actual heating knobs that have broken off be a problem if they are full on? as they are broken they just get turned to full capacity or what we think is full capacity but would this cause the overheating and the boiler to shut down the rads become unbearable to touch they are so hot it could be dangerous to a child but we have now put thermostats on each rad as this was suggested that this may be the problem also???

 

[transam]

Small flat ?? how many rads ?? boiler is on max' trvs on low ? the boiler probably has no way of dissapating the heat , come across this scenario in small propertys on several occasions !

Boiler has probably never been range rated either ??

 

[thurwood]

Small flat ?? how many rads ?? boiler is on max' trvs on low ? the boiler probably has no way of dissapating the heat , come across this scenario in small propertys on several occasions !

Boiler has probably never been range rated either ??

Hi There are only 3 rads quite close to one another I was told boiler is too powerful??? What should we try and do about this?

 

[thurwood]

Small flat ?? how many rads ?? boiler is on max' trvs on low ? the boiler probably has no way of dissapating the heat , come across this scenario in small propertys on several occasions !

Boiler has probably never been range rated either ??

Hi There are only 3 rads quite close to one another I was told boiler is too powerful??? What should we try and do about this?

Oh by the way the TVR's were only added recently as someone suggested this may help but it didn't! The problem with the boiler turning off has been a problem for a long time now

 

[transam]

Turn your boiler stat down , make sure at least one rad is fully open , get some one to check your boiler's gas pressure & range rate the heating to its lowest setting , not all the rads should have trv's , you should have a room stat fitted ?? the rad in the area of the room stat should not have a trv ! boiler has its own by pass but it may not be enough !