Boiler Condensing Y/N?

[Fly100]

Hello fellas,

 

Stupid question, if a boiler is giving out white smoke / steam from its exhaust is that an indication its condensing ? The drian pipe is a decent run and I cant see any water dripping out the end of it.

 

Thanks,

FLY

[JohnMo]

Less steam = more condensing.

 

The white steam is water vapour, a condensing boiler condenses the water vapour back to water and collects the latent heat, transfering it the heating system. To get condensing the return temp on a gas boiler needs to be below 56 degs (?). The further below that temp the the greater the condensing effect and more efficient the boiler runs.

[Olf]

  

On 25/11/2022 at 10:33, JohnMo said:

Here is a simple graph. 

 

Sorry about posting yourself @JohnMo, but this picture says it all!

Edited December 6, 2022 by Olf

[JohnMo]

12 minutes ago, Olf said:

Sorry about posting yourself

No problem, it does tell a better story

[billt]

1 hour ago, JohnMo said:

Less steam = more condensing.

 

I think that you will always get a plume from a condensing boiler, it's not likely that they are going to be able to condense all the water vapour.

Mine always produces a plume, yet the flow temp this morning was about 52C and the return 35C. Even when reheating the cylinder with a flow of 72C, the return was 46C. Denser plume when heating the cylinder, but still a plume when heating the radiators.

 

Might be worth checking the drain for a blockage.

[Fly100]

To be fair when I checked last night it was chucking down, and everything was wet. Im on oil for condensing stops at 47C. Im trying to get my return temps down, but keep passing the 47C ( self imposed limit).Rads are balanced but im running Rads upstairs and Underfloor down stairs both with vey differnet demands.

[JohnMo]

Looked at my boiler this morning 2 degrees outside, and there was white smoke.  Not much, just a general stream out the flue. Return temp at that was high 30s.

 

There will always be some water vapour, even if the flue temp was 30, flue gas would hit the cold air, exceed the dew point and water vapour would appear.