Yellow Flame manometer install question

Hopefully getting ready to fire up my boiler in the next day or so. A few details to complete, one being the Dwyer 25 install. I've searched and read a gazillion posts on manometer installs but most pertain to stoves. The Yellow Flame is similar to a Keystoker KA-6. I've seen some posts showing Keystoker provides a hole in the fire door for over the fire draft measurements. No hole in the Yellow Flame Door.The Keystoker door appears to be gasketed whereas the Yellow Flame door just sets in a groove when closed. A decent fit but hardly airtight. Before I drill a hole in my 30 year old cast iron fire door I thought I should ask the experts. Should I install the manometer in the flue pipe before the baro or in the fire door or should it be install some other way?
Thanks in advance for you help, what a fantastic forum!

You only need to check the over-fire draft for the initial setup of the baro and stoker air adjustment. I would monitor the draft routinely from the flue pipe between the boiler and the baro...right after the boiler is best.

I wouldn't feel good about drilling that cast iron door either. Can you cut a piece of steel and drill a hole in it? All you need to do is get the boiler up to temperature and hold the cover plate over the door opening to get a draft reading. In the absence of any other recommendation, I'd set the baro on -0.05", set the air at 1/2 open, and see what you get at the firedoor.

Matt Direnzo would be a good person to ask for advice on this, he is no stranger to Yellow Flame boilers: YELLOW FLAME

Thanks Rob for the quick reply and excellent idea!
I set up the manometer to take its reading just after the flue collar on the boiler. I also cut a piece of 16 gauge to fit the fire door opening and installed a fitting with a few feet of tubing. A quick swap of tubing at the Dwyer and I can take my over fire reading when I'm ready.
Getting closer.........
More questions to come I'm sure........
Thanks again for your help!

First fire in the Yellow Flame today! I did as you suggested Rob and set the baro to 0.05 (although its extremely windy here today and that has proved to be a moving target) air at 1/2 and the over fire at the fire door was 0.02.
And yes I've included a picture! I hope!
Is the over fire number close to where I should be?
Thanks again!

I think your draft is fine just the way you have it. How long had the stoker been running when you took that picture? Any idea what the feed rate is set at?

I'm guessing on the time but I would say 4 hours. I have six "holes" for feed rate adjustment. If we would number them 1 - 6 shortest stroke to longest stroke I am on number three.

I meant how long had the stoker been running continuously. You want to make sure on long burns (30+ minutes) that you still have an inch or so of ash on the grate. Since you have aren't running the feed at a high setting, it is probably fine the way it is. let it run thr way it is, have a warm Xmas, and keep us updated.

Will do!
Merry Christmas!