Plumbing K-8 With Existing Fuel Oil Fired Boiler

Just some basics to get this rolling. I will get pics of existing setup tomorrow to help with suggestions. House is approx 1800 Sq feet, well insulated and brick sided. Baseboard hot water throughout. Single level. I had purchased the k-8 for my previous home which was much larger, so yeah, it's kind of overkill. ..until my 30x50 shop gets put up. Here is my main goal: I drive semi and do two overnights power week. The k-8 would typically hold its own over that 40 hour period, but, if I should break down, I'd like to have the oil fired unit take over to maintain some kind of temperature control in my absence. I live alone. I've read to plumb in series and set the oil unit aquastat lower. Am I going in the right direction with that thinking? Both units will be in the basement, side by side. Thanks in advance for your time, the advice provided here on my original install was great, I love that keystoker!

You can do it that way. There are other options as well, but posting pictures of the existing boiler is a good way to get ideas.

Thank you! I will get some pics this evening.

Here's what I've got. Hope they upload.

Same one twice, but it gets the idea across.

Looks like two tee's should do it. Make sure your oil burner aquastat goes low enough. Mine on my propane boiler doesn't go low enough so I have to shut it down in the winter until I buy another aquastat.

Keystoker has a very easy to read near boiler piping for the kb8 that I would follow if I were you.

The only thing I don't like is they have the circulator up in the rafters.

On my first install with this unit, I followed their close boiler routing exactly sane for mounting the circulator on the cold side. It worked very well and plan to re use as much as I can.

What's the story with that circulator hanging by the BX cable?

That pump was locked up tight. My grandmother complained of no heat in a couple rooms for years, they added a fancy t-stat and basically blew smoke up her rear. When I bought the place, I heard the pump humming along but it was hot as heck and the copper lines were cold. Can't believe it didn't trip a breaker or burn the place down. I swapped my spare taco in there and am in the process of running dedicated power to that panel, as the feed is tied in with too many circuits imo.