No because it has no premix burner (so air intake not regulated) and the fan doesn't modulate. Hence they are less efficient at part load/modulation. At low stat setting they simply cut out when set temp is reached but the POC's won't drop to dew point during firing as already explained.
Follow up to condensing Combi exemption
- Thread starter JohnHarrison
- Start date
- Status
No because it has no premix burner (so air intake not regulated) and the fan doesn't modulate. Hence they are less efficient at part load/modulation. At low stat setting they simply cut out when set temp is reached but the POC's won't drop to dew point during firing as already explained.
Sponsored Links
So run it as low as you can to improve efficiency? (in a normal short flue)
You can't change it's efficiency. It will modulate whenever it gets close to set to temp, low or high, During modulation it's efficiency drops. Many non-condensing boilers are spot rated and don't modulate at all. You need to set it according to the design of your system. Traditional rads will not work properly with flow temps below 60 whatever the boiler so it needs to be above that. With range rated boilers you can also cap their output to suit.
I love this thread.
SARA is good but even better on a condensing boiler.
The condensate forms at different temperatures dependant on the excess oxygen relative to that required for combustion. 59° if perfect and lower the more oxygen. As the Compact SE has a fixed speed fan so as the modureg on the gas valve lowers and restricts the amount of gas being burnt the percentage of excess oxygen to gas increases.
54/55° is accepted as a general guide.
There are plenty of 25 and 30 year old Vokeras still out there with washed copper heat exchangers still going strong (same principle as that in the SE Compact and Vaillants et al).
Your Compact is a boiler sold still across Europe under different badges in countries slow to change to high efficiency products. It's been around for over a decade and to supply the UK with an exemption model a modern PCB control board was added to the standard boiler. Used to be the Compact e.
There is nothing special about the flue, it is a standard flue. To use in a SE or U duct the terminal cowl is removed and the tubes cut to length.
A condensing boiler is more than 7% improved efficiency also. The overall efficiency depends on so much outside the boiler.
There are no perfect boilers nor are there perfect installers or forum members. Boiler life depends to a large extent on how carefully it is installed.
If you are warm and happy, job done. If your guy puts in enough of Vokera's in a year he will be an approved installer and you will get 5 years rather than the standard two.
SARA is good but even better on a condensing boiler.
The condensate forms at different temperatures dependant on the excess oxygen relative to that required for combustion. 59° if perfect and lower the more oxygen. As the Compact SE has a fixed speed fan so as the modureg on the gas valve lowers and restricts the amount of gas being burnt the percentage of excess oxygen to gas increases.
54/55° is accepted as a general guide.
There are plenty of 25 and 30 year old Vokeras still out there with washed copper heat exchangers still going strong (same principle as that in the SE Compact and Vaillants et al).
Your Compact is a boiler sold still across Europe under different badges in countries slow to change to high efficiency products. It's been around for over a decade and to supply the UK with an exemption model a modern PCB control board was added to the standard boiler. Used to be the Compact e.
There is nothing special about the flue, it is a standard flue. To use in a SE or U duct the terminal cowl is removed and the tubes cut to length.
A condensing boiler is more than 7% improved efficiency also. The overall efficiency depends on so much outside the boiler.
There are no perfect boilers nor are there perfect installers or forum members. Boiler life depends to a large extent on how carefully it is installed.
If you are warm and happy, job done. If your guy puts in enough of Vokera's in a year he will be an approved installer and you will get 5 years rather than the standard two.
Sponsored Links
I have, around 4 or 5 times now. Thank you for just proving my point 
Thanks. Which condensing boilers are spot rated?
I am getting five years which amazed me.
"A condensing boiler is more than 7% improved efficiency also. The overall efficiency depends on so much outside the boiler."
I think that is in like for like installations. He said that most condensers are not as efficient as the makers make out and that a non-condensing boiler can near match a poorly installed condenser.
This got me this thinking of the after market DHW preheaters that go in the flue to capture wasted heat from a combi. The cold water runs around a coil in the box which the flue gases run through. Put one of these on a non-condensing boiler and it is converted into a condensing boiler, but still with the ridiculous plume out of the exhaust.
Doesn't the condensation drop on the ferrous burner and other parts of the burner box? I believe with condensers they have the burner at the front (top) of the heat exchanger, so condensate runs away not contacting burner and other parts.
I would have thought the hot gas pipe would have a bend on it pointing upwards in a U-duct. If it is straight the flue exhaust gasses would hit the opposite side of the U-duct. I know some guy who lives on the upper floor of a tower block and he says in winter the U or Se-duct gets warm and helps heat his flat.
You really can't help showing your ignorance.
My assessment of you was totally correct.
Likewise, but I would suggest that you refrain from to many assumptions on how combustion and condensing in the flue. It is like watching a train wreck in slow motion.
Was only the other day I was looking at some beefy water heaters that not only condense, but have an atmospheric burner, variable speed fan and copper finned heat exchanger.
Was only the other day I was looking at some beefy water heaters that not only condense, but have an atmospheric burner, variable speed fan and copper finned heat exchanger.
Not sure how I can explain his any clearer
NON-CONDENSING BOILERS DON'T CONDENSE IN THE COMBUSTION CHAMBER. THERE IS NO CONDENSATION FOR THE BOILER TO DISPOSE OF.
Any suggestion your installer has made about controlling F/R temps to prevent condensation in SE boilers is TOTAL B*******.
SE Boilers on very long oversized flues such as the Vaillant 80/125 system had a trap connection on the flue turret to dispose of condensate from the flue system, but never the boiler's chamber.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
- Status
Sponsored Links
