pre heat disablement kit

[smileyplumber]

Right I know there rubish but I was called to an IDEAL ISAR 30 yesturday to fit a Pre heat disableing Kit
basicaly a flow switch and a bit of pipe .
the customer complaining that the boiler fires up every half hour or so to pre heat it's self costing her gas , so she gives me a call and say can you fit me this part gives me the cade etc I goes up fits it.
Now so far so good the original set usess a thermistor to measure water temp to bring boiler on when tap runs the water goes cold boiler fires .
she rang me today to say it came at 4 am then 5 then 7 no heating just boiler fireing up then going off .
didnt say if it had done it since .
I will say when i fitted it and tried it out the flow switch doesnt shut the boiler off (d) mode when the tap is switched off it keeps going for 20 seconds or so .

So have any of you guys out there come across these things or had any problems as above any Ideas welcome although she wont let me change the boiler 🙁

 

[gas46]

hi to diagnose it properly you need to see what is in display when it comes on, isars are very sensitive to any flow in the dhw circuit even a dripping tap will bring on the boiler the shut down delay and the pre heat problem may be related if there is a dead leg or leak on dhw side it would cause this issue best way to test is to run hot tap then turn of cold water inlet under boiler if it shuts down straight away then problem could be more plumbing related than a boiler issue

 

[diamondgas]

Never heard of the kit smileyplumber. It would have to be wired in in such a way as to interupt the PCB detecting a drop in the h/w thermister though I'd assume! I'd be interested in knowing how that's done as it'll involve some clever electronics to fool the PCB into thinking the pre-heat wasn't needed! It all sounds a bit dodgy to be honest!!! 🙂

 

[smileyplumber]

hi to diagnose it properly you need to see what is in display when it comes on, isars are very sensitive to any flow in the dhw circuit even a dripping tap will bring on the boiler the shut down delay and the pre heat problem may be related if there is a dead leg or leak on dhw side it would cause this issue best way to test is to run hot tap then turn of cold water inlet under boiler if it shuts down straight away then problem could be more plumbing related than a boiler issue

I did operate the tap from the boiler cold inlet with tap fully open I allso checked the flow switch wasnt sticking too ,
but that doesnt explain why it fire up through the night either .
I did see a radio frequency sat reciever next to the boiler but even if that were to be sending a confused signal i cant see it bringing boiler on .

diamondgas it's an ISAR mate it is all ready dodgy lol but you are corect it does interupt between stat and pcb

 

[armourer]

Its not firing up on a frost stat is it?
Remember you wasn't there to see the display and we have had some cold nights?

 

[diamondgas]

diamondgas it's an ISAR mate it is all ready dodgy lol but you are corect it does interupt between stat and pcb

Is this something supplied by Ideal? If you interupt the detection of temp drop then how, when you turn a hot tap on, does the boiler know you have? The h/w thermistor detects temp diff in the inlet of the plate hex on the Isar doesn't it?

EDIT ---- Just googled the kit and it is made by Ideal!!! Weyabugga..! Always learining here 🙂

 

[smileyplumber]

I just fitted the part i dont make em .
frost stat is a valid piont armourer i didnt think about that and of corse it;s fitted in a roof void

 

[diamondgas]

I just fitted the part i dont make em .

Sometimes helps to know how they work though eh? IMHO 🙂

 

[smileyplumber]

Sometimes helps to know how they work though eh? IMHO 🙂

aye it helps but when the customer is standing over your shoulder asking all the questions under the sun some times ( and i dont care how experienced you are ) it can put you off lol .

anyway i can see how it works I just got a little lost along the way hence I asked you guys 🙂

 

[diamondgas]

aye it helps but when the customer is standing over your shoulder asking all the questions under the sun some times ( and i dont care how experienced you are ) it can put you off lol .
🙂

They can be a right pain when you aren't 100% sure yourself to be honest 🙂 I tend to say something along the lines of "answering all these questions is drying my throat out..." hint hint 🙂 Can divert them towards being a bit more hospitable when you want them out of your hair ... lol

 

[smileyplumber]

the guy was an ex catering fryer maintanance fitter :75: retired at that you dont stand a chance really

 

[diamondgas]

the guy was an ex catering fryer maintanance fitter :75: retired at that you dont stand a chance really

Well hopefully its the frost stat kicking in 🙂

 

[Billy Bob Bob]

just buy him a axe,bill him for said axe and your time he may be confused why you supplied a axe but its a proper ideal part part number is 0987654321 ifeelbetternowihavekilledtheisardead

 

[dcawkwell]

Never heard of the kit smileyplumber. It would have to be wired in in such a way as to interupt the PCB detecting a drop in the h/w thermister though I'd assume! I'd be interested in knowing how that's done as it'll involve some clever electronics to fool the PCB into thinking the pre-heat wasn't needed! It all sounds a bit dodgy to be honest!!! 🙂

It wouldn't need anything special. A simple resistor connected all the time to bypass the existing thermistor in the boiler
to fool the boiler into thinking the water is hot. A flow switch via a relay connects the normal thermistor up as soon as water is flowing and normal operation of the boiler is as before. Not that I would waste time on Ideal boilers. The best place for an Ideal boiler is in the nearest skip.

 

[diamondgas]

It wouldn't need anything special. A simple resistor connected all the time to bypass the existing thermistor in the boiler
to fool the boiler into thinking the water is hot. A flow switch via a relay connects the normal thermistor up as soon as water is flowing and normal operation of the boiler is as before. Not that I would waste time on Ideal boilers. The best place for an Ideal boiler is in the nearest skip.

That makes perfect sense dcawkwell 🙂 maybe you should patent it for all the other boilers where you can't interupt the pre-heat 🙂

 

[buckley plumb]

dug my old issar training book out the boiler detects a hw demand by the thermistor on the plate to plate. the boiler burner will keep on even when the tap is off untill the thermistor detects the temp increas normaly 20 - 30 secs .this is normal opperation

ant

 

[smileyplumber]

dug my old issar training book out the boiler detects a hw demand by the thermistor on the plate to plate. the boiler burner will keep on even when the tap is off untill the thermistor detects the temp increas normaly 20 - 30 secs .this is normal opperation

ant

even after the interuptor is fitted ?

 

[buckley plumb]

even after the interuptor is fitted ?

no not then ,

ant