thermostat relays, controls efm 520

hurray the new used efm 520 is in the basement and it is time to get it running after 4 weeks of concrete and masonry work now it is plumbing and electrical, I would like to set up 6 zones on my efm520 boiler and domestic hot water does any one have any suggestions on controls, I have a mix of cast iron radiators and hydronic heat two story house 1100 square feet per floor, hydronic in slab in basement zone, cast iron radiators main floor main zone, under floor hydronic in 2nd floor bath and cast iron radiators in three bedroom zones second floor, all 3/4 cu piping is run in walls from past renovations and open basement where boiler is located... I am hoping to get this work done by next week and fire it up as it is getting cold and am sick of feeding hand fired boiler

Congratulations ted! Sounds like you have a nice system there, and note that you have converted from manly man to girlie man!

See folks, even the best (ya gotta say that a hand fed boiler is manliest of manly!) of the manly men is subject to conversion.

Now that I got that sillyness out of the way, how do you have your zones split up. I am interested in this because I am planning on removing a bath room kick plate heater on the current upstairs hydronic loop and converting it to radiant. Wasn't sure if there would be any issues with mixing baseboard and radiant in the same zone.

Best of luck with a speedy mechanical/electrical install.

Hi Ted. You need tempered water temps for the hydronic floor heat. I'm pretty sure you need to plumb in a mixing valve so the cold return water from these circuits is recirculated with a controled amount of hot water from the boiler. I'm not sure if you will need a different controler for each hydronic circuit or not.

The concern is that you don't want to get the 'hot foot' treatment by running full temp boiler water into the floor, especially the bathroom floor. I think floor temps over 85* or so becomes uncomfortable.

You want full temp boiler water for the cast iron radiators.

You should have an aquastat, a Honeywell 8124 is the normal one. You will use this to turn on the circulator and the coal stoker.

I'd probably use regular zone valves for the various zones. With six zones, do you have the wiring installed for six thermostats to control the individual zones??? Usually one zone per floor is what I've had, but you may want to improve on this for more flexibility..

Or you can use one zone valve for each floor and use ball valves to control flow to the various water circuits [sub-zones] on each floor, this way you manually adjust the water flow/temperature for each sub-zone, and use a thermostat for each floor level main zone.

Many ways to do it, depends on how creative you want to be.

Greg L.

matt- thanks for the reply I didnt know this was going to affect my manliness just thought that it would affect my laziness and overall comfort level of the house
I havent yet installed the radiant to bath floor second yet there is a cast iron radiator in there but I will run radiant under floor after i get boiler running... All of the rooms in house have two pipe run to individual radiators so it will be easiest to isolate rooms into zones when i do plumbing....
Iam going to tile the bath floor hopefully this will keepp it much warmer so the girls will not run the electric vent fan heater unit , but will run the exhaust fan instead

you are still a manly man shoveling coal over the auger once a week I won't offer any advice on plumbing because I;m not very good at it.