high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at full

[mickeyuk]

in service mode and boiler on max the flue temp goes way up to 90c all other reading are ok . i rang Worcester and they said it was ok but i wonder if its the towel rail first of the boiler causing the high temp no thermostatic just lock shields. in hot water only mode tap full on its 68c .Although none of the thermostatic s had shut down in service mode and with hot tap running still high flue gas readings 90c after 8 mins full rate. ratio 0.0010- ppm about 100 on max- meter working pressure 20.5 gas valve 19 on max

 

[desrob]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

does seem a little high,but whats your concern,every thing else in order.

 

[mickeyuk]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

hi desrob thanks for you rep lie im more worried about the temp and the plastic flue what temperatures can these cope with thanks

 

[diamondgas]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

Think about how a boiler works MickeyUK 🙂 I'm guessing you had this on water only yeh? There's only so much of the heat generated that'll be absorbed 'top end' of supply .. The rest will be waste yeh?

 

[mickeyuk]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

HI Diamond hot water only 68oc service mode 90oc hot water and rads

 

[desrob]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

Think about how a boiler works MickeyUK 🙂 I'm guessing you had this on water only yeh? There's only so much of the heat generated that'll be absorbed 'top end' of supply .. The rest will be waste yeh?

does the 28i condense in both hot water and central heating,i'm not sure they do,so maybe not high at all

 

[diamondgas]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

So what would make the exhaust get to such a temp? It will condense on both hot wate and heating desrob you're right! Is 90[SUP]o[/SUP]C to hot? I honestly don't know the answer to that one but it's a darn sight cooler than conventional boilers 🙂

 

[mickeyuk]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

yes it does desrob thanks

 

[desrob]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

hi desrob thanks for you rep lie im more worried about the temp and the plastic flue what temperatures can these cope with thanks

and you have a sensor in there isolating the appliance if flue gasses get too hot...nothing to worry about mate

 

[Destroyer2813]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

Stat will trip it out before the flue can melt wouldnt worry bout it

 

[mickeyuk]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

Thanks for your help Desrob

 

[tamz]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

i wonder if its the towel rail first of the boiler causing the high temp no thermostatic just lock shields.

What would that have to do with the flue gas temperature?

 

[Nostrum]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

The boiler will never ramp up to max ie service mode in normal operation anyway, it's purely for setting the range on the gas valve so nothing to worry about IMO

 

[ManchesterGas]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

It's a chimney sweep function for cleaning any crap out of the flue, it's supposed to get hot!

 

[mickeyuk]

Re: high flue gas temperature readings of 90oc on Worcester 28i condensing boiler at

I always thought that a condensing boiler with flow and return temps near the same would cause a rise in flue temp and boiler would not condense as it should.Thats the way i told years ago ! ha The return temp has a lot to do with flue temp and a bypass should not be off the boiler it should be at the far end of the system As for the 28i in service mode the diverter valve moves to mid position giving hot water and heating thats why you open the hot tap !When this boiler was in service mode flow and return temps were too close hence the rise in flue temp. Cause crap system