sime super 90.help ?

[gingerbear]

hi guys ! new to this site so please bare with me yeah ! i have a sime super 90 combi boiler ! it seems to stop producing hot water for a very short period brifely whilst having a shower and the shower goes cold then the boiler starts up again and away we go again and so on. the divertor was replaced last year(complete not just the diaphram). could this be a D.H.W thermister problem or a partially blocked D.H.W heat exchanger ? any help would be most appriciated and thanks in advance !

 

[Agile]

Most likely to be a blocked heat exchanger but to confirm that you would need to measure the flow and return temperatures on its primary connections and see if they are excessive. Should be about 15-20 C.

Tony

 

[xr4x4]

does it do it if you run the hot tap full, or have the shower full on hot only?

 

[gingerbear]

does it do it if you run the hot tap full, or have the shower full on hot only?

thanks,it does'nt seem to do it on the hot water taps but defo on the shower when its on hot only if that makes sense ! all of a sudden i now have a misses who has become a plumber over night and says its the bloody shower ! as if i need this ! help !

 

[xr4x4]

try running a hot tap slightly then use the shower, see if it makes a difference.

if the boiler isnt detecting enough water flow, or if the water is slow moving and reaches temp it will shut down. hence why the water goes cold.

this maybe a fault or just a feature of combi boilers when matched with some showers.