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Jen_in_ NE
Need Help with Multi Zone hot water heating

Ok, here's my situation.

I live in house built in the early 1900's, though I'm not sure of the exact year. It's been through some remodeling, particularly finishing the attic space into a large family room type space.

The boiler is in the basement and the main floor has the original cast iron radiators in all but the kitchen and dining room which have the baseboard hot water heaters. The finished upstairs also has baseboard hot water heaters.

Two years ago (2010) a new Crown Boiler (AWI162ENST1PSU) was installed due to the old one having a gas leak. However, when this was installed, there were no valves placed on the supply and return water lines for the upstairs. However, the plumber who installed the boiler DID attach a thermostat to the boiler, one for the main level and one for the upstairs. We were constantly fighting with the temperature on the lower level and wound up having to use a (good/expensive) space heater in the upstairs to keep it warm in the winter.

Recently, we called a new plumber to come out and look at the system (as the installing plumber has failed to "come look" at the issure for over 1 1/2 years despite repeated calls) to try and figure out why we didn't get heat upstairs and got too much downstairs. We were told when we moved in that you had to "mess" with the upstairs thermostat to get the main level one to work properly. Last year wasn't so bad, but this year we wound up waking up to an 85 degree main floor in the mornings.

Ok, so long story shortened. The boiler installed is verifiably a hot water boiler. The radiators on the main floor, based on my research are hot water radiators, though research also says that they can be used for steam heat. They each have a hot water air vent (standard screwdriver type)located about 2/3 of the way up the radiator on the opposing side of the supply line. On the main floor they are two line radiators, supply and return I assume though I'm not certain. The upstairs baseboard radiators are for hot water, and have one supply line coming from the basement to the RH side of one radiator, then copper line runs the perimeter of the upstairs space with 2 additional HW radiators connected inline. The return line is on the LH side of the last radiator.

So, the plumber indicates that our boiler is running at too high of a pressure. He says he needs to replace the expansion tank since bleeding the pressure relief valve doesn't bring the pressure down, and he disconnects the thermostat to the upstairs (both thermostats were connected to the boiler at the same point and there are no valves to control the thermostat for the upstairs area).

When I asked him about creating a separate "zone" for the upstairs, he tells me that the whole house would have to replumbed, including tearing out walls to do so. He tells me that it is a steam boiler, and that the radiators running on the main level are running on steam, and that the radiators upstairs are for hot water. This isn't true, as the supply and return lines run through the main floor outside of the walls. When I explained that to him that's when he said it was a steam boiler and all the main floor radiators were operating on steam, not hot water.

Is this even possible? I understand that the house could have been plumbed that way, but can you connect a hot water boiler in such a way to heat with steam? I also understand that many people who have worked on this house for the elderly owner took advantage of her absence and lack of knowledge while they worked (such as the guy who connected a non-zoned heating system to two thermostats "just because" that's the way he found it).

How can I tell if my radiators downstairs really are operating on steam and not hot water? Would the boiler, rated at 162,000 input and 132,000 output have enough pressure to re-plumb the supply and return pipes for the upstairs into a separate zone?

The radiators work fine, are not noisy at all, and have no visible signs of leaks, now or in the past.

Anyone with any suggestions (who's managed to make it all the way though this post) is not only tenacious but also very much appreciated.

Please help.

Re: Need Help with Multi Zone hot water heating


You have a hot water heating system, not steam----it sounds like you've had the bad luck of having incompetent boiler service people working on the system so your main task is TO FIND A CAPABLE, KNOWLEDGEABLE BOILER TECH who knows what he/she is doing.

It sounds like several of the radiators are leftovers from an earlier steam system & have bleed vents near he middle of the rad; these have to be modified so that the bleed valve is at the top of the rad (where the air accumulates), and the mid-point vent plugged & eliminated---but these are minor issues; the main task is to have a good heating tech re-arrange the heating pipes so that you eventually have 3 separate heating zones in your house, each with its own T-stat, heated by the same boiler.

Consult the Yellow Pages under "Heating Equipment & Systems" to find the heating parts distributors in your area & go down in person and talk to the PARTS COUNTERMAN, saying you have a HW heating system & you need a good technician/contractor to modify the pipes & service your system.

Try visiting some of your local real estate agent's offices---they deal with heating contractors often & can refer you to a reliable heating contractor/technician who will do a good job of examining your heating system & coming up with the best plan at the lowest cost to make the needed modifications that will give you good heat on both floors, as well as the attic addition; if you don't have any success using word or mouth, or contacting the businesses mentioned, another tactic is to join one of the internet contractor evaluators, such as the Better Business Bureau, or perhaps Yelp, or homeadvisor.com, or Service Magic---these are all free of charge, but are sometimes limited in the # of contractors they evaluate in your area; if you have no luck with the FREE referral agencies, try a one month subscription for $8 to Angie's List---I've had good luck with this service so far, and have heard mostly good things about the referrals they make---if you pay the $8, they will show you a list of a number of contractors that customers before you have hired, and emailed in a good or bad report on the job they have done---so your task is simply to call the contractors who have nothing but GOOD reports returned on them for the work they've done for other customers before you.

Always get at least 3 estimates from separate heating contractors and their price quote in writing, as to what modifications you need to your heating system.

My reading of your post indicates that you have an excellent forced hot water Crown Aruba boiler that will do the job of heating the house, but the installer just connected the 2 T-stats for the 1st & 2nd floors in series, which is a dumb thing to do & clearly won't work to get adequate heat in both floors, let alone the attic addition-----what you need is a heating tech who will install a ZONE VALVE for the 1st, 2nd & attic floors at the near-boiler main piping and run a T-stat wire to each of the 3 floors so that you will have control of the heat on each floor---that's the rather easy part----the more difficult part is that the PIPING will have to be RE-ARRANGED, beginning in the cellar, so that EACH FLOOR HAS ITS OWN PIPING LOOP---each one of these piping loops will have its own zone valve, and its own T-stat, but the job requires (as noted in your post) that the walls be opened up here & there, and new pipes be installed to create 3 separate piping loops---this is not to say that they will have to rip ALL the walls open, they use HIGH-TEMPERATURE FLEXIBLE PLASTIC PEX pipe these days, that can rather easily be snaked thru the wall cavities to create the 3 separate zones that you need for your heating system---the CALEFFI site below illustrates how this looks on a diagram of the boiler and the various zone valves that are installed---the hash-marks indicate the heating element---this can be a combination of baseboard, cast iron rads, or even the newer stainless steel rads in any combination---the heating technician first has to do a HEAT LOSS CALCULATION for each floor of your house to determine how many BTUs per hour of baseboard and radiator heat output will keep the floor comfortably warm---this is a once in the life of the house ownership that it has to be done, so I would strongly recommend that you have it done; at the Caleffi site, Figure 3-7 illustrates the zone valve setup & how it connects to the boiler piping; the "hash marks" indicate the baseboard/radiators that are connected to each "zone"----the illustration in this case depicts 4 zones installed in different areas of the house----notice how each of the "loops" are separate and controlled by their own zone valve---these loops are usually of 3/4" or 1/2" piping, while the near-boiler piping is much larger (1 1/2")---not shown in the illustration is the T-stat wire that is connected to each zone valve that goes up to each floor in the house where the T-stat is located to control the amount of heat for each floor; Figures 4-7 & 5-7 show the new stainless steel radiators connected to separate zones.

How a zone valve heating system works: When a room or floor in the house starts getting cold, the T-stat on the wall senses the drop in temperature and closes its electrical contacts & sends a 24 volt current to the zone valve controlling that zone/floor; once the zone valve completely opens, it closes a switch (end switch) that sends a 24v electromagnetic current/voltage to the main boiler switch (aquastat) that "pulls in" a small metal plate that closes a 120v switch to allow the boiler water pump and the oil burner/gas burner to activate to start heating the boiler water & pumping it to the zone that is calling for heat; as the room heats up, it eventually opens the T-stat contacts that shuts down the oil burner/gas burner---the pump continues to pump hot water into the heated room (override) until the pump shuts off; the zone valve switch opens and the valve inside the zone valve closes, completing the cycle.

The FIRST thing you should do is to call an insulation contractor (Yellow Pages: Insulation Contractors) to determine if your exterior walls have no insulation---the insulation contractor has a truck with a blower that blows cellulose insulation into every corner & nook of the exterior walls so that any heat produced by the boiler STAYS INSIDE THE HOUSE---also have all the windows checked out that they are double-pane new windows or are storm windows--this is also essential for keeping the heat inside the house---these 2 procedures will SAVE YOU A TON OF MONEY ON HEATING BILLS, as well as cooling bills in the summer---so it's well-worth any money you spend on these 2 preliminary projects.

If you are using the internal HW coil inside the boiler for your domestic hot water (DHW)(showers, dishwashing, cleaning, etc.), I would recommend you consider also buying a companion 40 gallon INDIRECT HOT WATER HEATER so that you can have adequate hot water for showers, etc.;---this of course can wait if you are not constantly running out of DHW, until you complete the more important project of zoning off the piping of the heating system.

From your post it sounds like you made the wise choice of getting an excellent Crown Aruba boiler that should give good service for many years to come---it also sounds like you will be able to use all of the existing baseboard elements, as well as most, if not all of the cast iron radiators, since you note that none of them are leaking---always try to hold on & use the cast iron radiators, they emit much more heat than the baseboard elements, and stay hot a long time, wheras the baseboard emits its heat & then rapidly cools off.


MLB Construction
Re: Need Help with Multi Zone hot water heating

if there is a sight glass on your boiler, a glass tube that should be half full of water, that means you have steam heat. another way to determine that is by looking at the radiators. if the radiator has one pipe going into it on one end and nothing on the other, then it's steam heat. if there is a pipe going into the floor on both ends then you have a hot water system. if you have a hot water system you now have to determine if you have a forced hot water system or a gravity hot water system. if there are one or two curculator pumps by the furnace then it's forced hot water, if not it's gravity. now, if you have a gravity system the first floor will normally be considerably warmer then second floor because the hot water takes longer to reach the second floor.

can you post a pic of your boiler?

also, if you have baseboards in some of the house i highly doubt that you would have steam heat.

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