saunier duval

[paulfrench]

hi
i have had a saunier duval combi boiler for about 6 years. i have recently had nearly all of the parts changed because the heating was only running at 44 degrees and i still have the problem. the hot water is fine its just the heating side of it. my plumber has now give up trying to solve the problem. Does any body have any other solutions or is it time for a new boiler.
thanks paul

 

[oldplumber]

basics first,is the heating temp on the boiler set high enough (control switch broken off?), is heating potentiometer set correctly (see commisioning set up instructions) are the dip switches set correctly, is your bypass open to far,heating thermistor working correctly? a few starters for 10
. Finally does your plumber know what hes doing? just replacing parts to resolve the problem isnt the best way to resolve the fault, you need to find the fault then replace the faulty item!
Also exact model number of your boiler makes things easier to comment on problems

 

[paulfrench]

hi oldplumber,
yes all the basics have been checked and are all set ok. the thermistor has been changed the pcb board and the wiring loom, the system has been flushed and we have run out of ideas do you have any more ideas that may solve this problem. I have spoke with saunier duvals tech dept and they have not come across this problem before good tech dept they are. Anymore ideas let me know
thanks for the help
cheers paul

 

[Bernie2]

Basics I suppose:

If the heating is only reaching 44 then it seems obvious that either its a control problem or the radiators and circuit are far to big for the boiler.

But then if left on long enough and enough heat is going into the circuit fast enough the temp should go higher regardless of the size of the circuit.

A bit like a candle heating a bath of water, providing the heat from the candle is inputting more heat than the circuit is loosing, it should at some point become as hot as the candle can make it.

So assuming yours is an average situation, the usual domestic boiler if its sized properly should raise the water temperature. If its not, it seems safe to assume it may be a control problem shutting the boiler down to soon.

 

[oldplumber]

concur with bernie there

 

[paulfrench]

i agree, the combi boiler is a enviroplus f24e it is fitted in a 2 bed terraced house with only 6 rads the boiler is more than enough for the property. it just seems a bit odd how it has just stopped functioning correctly now after 5 years. it is obviously something on the heating circuit which is stopping the boiler going above 44 degrees but what i dont know.

 

[stevetheplumber]

obviously something is stopping the boiler at 44 degrees most likly is a stat or thermistor id wire each one out in turn see if that makes a difference has anyone checked the overheat stat isnt comming in early or has wrong thermistors fitted just throwing in ideas as im not familiar with this model