Hello and apologies for writing in English, my Dutch is too far from enough for describing the situation.
I have a supposedly very old Calenta 40L (CW6) Combi Comfort Systeem met iSense. Apart from having to add some water since August when I moved in, there had been no issue until yesterday night, when my shower suddenly became cold (heating was off by then as I set it to lower values for the night). Unplugging the boiler didn’t help, although heating seemed to work. In the morning it was vice versa – hot water was okay, but heating wasn’t working for about an hour, then everything was normal – both heating and hot water were okay for some 4-5 hours. Then we noticed that the radiators were cold, and the room temperature was 1 degree lower than it was supposed to be.
I’ve spent most of my Saturday trying to understand what’s wrong and here’s what I noticed. When the boiler is switched off and back on, the outgoing pipe becomes very-very hot very quickly, even the radiator incoming pipes feel very warm, but it lasts for some 20-30 seconds and then everything gets cold again. During startup (which is very long, feels like 1,5-2 minutes) I can hear the pump turn on (and a “play” icon appears on the display) for 2-3 seconds and then off (“play” icon disappears), there are maybe 10 or more pump starts and stops like these before the display changes from “17 1,9 bar” to normal.
The info mode shows St:8 Su:0, which seems to translate to Regelstop, Wacht op branderstart (I also saw St:5 Su:41 once, which I believe is Branderstop, Naventileren). There’s also something I don’t quite understand (but I know almost nothing on the subject): t1 and t2 are always the same around 78 degrees, while from reading the manual I got the impression t1 is for the water going from the boiler (Aanvoertemperatuur) and t2 is for what’s being returned (Retourtemperatuur).
I’ve read some posts on this forum, and could blame the 3-way valve, but the fact that at startup it does get hot very quickly and the heat does reach radiators, plus this t1=t2 status make me doubt. I did add some water to the system (it had been 1,6 bar with the pump off and 1,3 with the pump on, now it’s 1,9 and 1,6 respectively) and bleed 3 of the radiators that were the easiest to get access to.
I’d appreciate any idea on what it can be, what else I can try myself and how much a repair should cost, because I literally have no idea. If it's indeed the 3-way valve, is there a way to at least check or perhaps even replace it myself?
There’s also a maintenance sticker from April, would you recommend contacting this company or doesn’t it matter at all (because according to their website they are in Schiedam, and I’m in Scheveningen)?
Thanks in advance,
George
I have a supposedly very old Calenta 40L (CW6) Combi Comfort Systeem met iSense. Apart from having to add some water since August when I moved in, there had been no issue until yesterday night, when my shower suddenly became cold (heating was off by then as I set it to lower values for the night). Unplugging the boiler didn’t help, although heating seemed to work. In the morning it was vice versa – hot water was okay, but heating wasn’t working for about an hour, then everything was normal – both heating and hot water were okay for some 4-5 hours. Then we noticed that the radiators were cold, and the room temperature was 1 degree lower than it was supposed to be.
I’ve spent most of my Saturday trying to understand what’s wrong and here’s what I noticed. When the boiler is switched off and back on, the outgoing pipe becomes very-very hot very quickly, even the radiator incoming pipes feel very warm, but it lasts for some 20-30 seconds and then everything gets cold again. During startup (which is very long, feels like 1,5-2 minutes) I can hear the pump turn on (and a “play” icon appears on the display) for 2-3 seconds and then off (“play” icon disappears), there are maybe 10 or more pump starts and stops like these before the display changes from “17 1,9 bar” to normal.
The info mode shows St:8 Su:0, which seems to translate to Regelstop, Wacht op branderstart (I also saw St:5 Su:41 once, which I believe is Branderstop, Naventileren). There’s also something I don’t quite understand (but I know almost nothing on the subject): t1 and t2 are always the same around 78 degrees, while from reading the manual I got the impression t1 is for the water going from the boiler (Aanvoertemperatuur) and t2 is for what’s being returned (Retourtemperatuur).
I’ve read some posts on this forum, and could blame the 3-way valve, but the fact that at startup it does get hot very quickly and the heat does reach radiators, plus this t1=t2 status make me doubt. I did add some water to the system (it had been 1,6 bar with the pump off and 1,3 with the pump on, now it’s 1,9 and 1,6 respectively) and bleed 3 of the radiators that were the easiest to get access to.
I’d appreciate any idea on what it can be, what else I can try myself and how much a repair should cost, because I literally have no idea. If it's indeed the 3-way valve, is there a way to at least check or perhaps even replace it myself?
There’s also a maintenance sticker from April, would you recommend contacting this company or doesn’t it matter at all (because according to their website they are in Schiedam, and I’m in Scheveningen)?
Thanks in advance,
George
