Regular Guest
Hello everyone. Found this site last night around 11:30pm and gorged myself on great info until 3:00am. I wish I found you guys many months ago. Our house (purchased in September) has a Weil-McLain Gold Oil boiler which heats the copper and fin baseboards as well as the DHW (didn't figure out what that stood for until about 1:30am). The house is a 2 level rambler with 4bd/3br with about 2600 sq/ft and has 2 zones (up/down stairs). We've had no issues with keeping the house warm but the DHW supply is paltry, can't get through a 10 minute shower. We're also going through heating oil very quickly, however, I really don't have a frame of reference on that. I have several questions so I guess I'll type them out in list form.
1. How can I tell the model number (and therefore figure out BTUs) of our boiler?
2. If I want to get an indirect-fired water heater installed would it use the DHW coil in the boiler or the baseboard coil to source the hot water?
3. I was told by a boiler tech that I could install an electric water heater in-line after the DHW coil but he never mentioned an indirect-fired heater. Any thoughts for or against this as an option? Should I be skeptical of this tech if he didn't mention the possibility of an indirect-fired heater? There's no easy way to get 240v to the boiler room so not sure how feasible electric would be anyway.
4. Would an outdoor reset switch help now or could/should I wait until closer to spring to get that installed?
5. Natural gas is available at the street but not at the house. Should I explore the possibility of converting to gas right now (before spending any more money on this setup) or do you think I can make this oil boiler as efficient and cost effective as gas (or close on either count)? I was told the boiler was installed within the last 10 years or so.
6. Can I purge the air out of the system or should that be done by a pro every time?
7. Are there other questions I'm not asking but should?
Here's a picture of the boiler. Thanks in advance. I have a lot to learn and I'll try not to post questions that have been answered a thousand times (already done some searching on these topics going back a few years).
Regards,
Patrick
Professional Member*
i would look into the gas conversion, you will NEVER get that boiler to be as efficient as a high efficiency gas boiler.
for now you might want to find a good boiler guy to service what you have, with that tankless coil you should never run out of hot water.
Professional Member*
1. As far as the model number, it should be on a tag attached to the boiler. Not 100% sure on that though. You should be looking for 3 or 4 letters followed by a dash and then a number. You could always post the info you find on tags and someone will be able to tell you what size it is.
2. If you get an indirect-fired water heater it should be plumbed into the boiler just like another zone. The DHW coil in the boiler I wouldn't use for numerous reasons.
3. Should you be skeptical of a tech that didn't mention and indirect? Not really. Not all techs are salesmen. I would question the company about the option and if they suggest the same thing then I'd be "skeptical".
4. An outdoor reset is a good addition anytime. With the type radiation you have it's probably not going to get you the top suggested savings though. Fin tube radiation requires higher temperatures than large cast iron radiation. The best starting point would be to do a heating loss on the home room by room. Take that information and match it against how many feet of baseboard you have in each room. Find the baseboard manufacturer's specifications for the type you have and it will tell you how many btu's/hr/foot you can get at each inlet temperature and flow. Knowing this information you should be able to get a good idea what the payback is on installing a reset control.
5. Switching to gas has a few advantages. My experience is that you will have less maintenance issues with natural gas. You "shouldn't" ever run out of fuel because you forgot to get the tank filled up. Depending on where you live and how many qualified oil service techs there are verses the gas techs you might find it easier to get one serviced or repaired competently over the other.
Again, with the baseboard type radiation you need to get your heating load numbers together before making any kind of decision about switching to gas. Meaning that if you think switching to a high efficient gas boiler because it's rated at 90%+ efficiency you need to realize that efficiency number is at much lower water temperatures than you might be able to heat your house with.
A modulating high efficient gas boiler would do a very nice job of dealing with the two zones and the addition of an indirect though.
6. Purging air out of a hydronic system is not normal maintenance. Actually it should never have to be done once the system is installed and up and running. If you're finding air in your system then there is a problem with something that needs to be found and fixed.
Pictures are worth a thousand words. The one shot you took of your boiler was just enough to make me go hmmmmmmmm. Mainly because it looks, from the angle you took the picture from, like the circulators are pumping into the return of the boiler and I don't see an expansion tank anywhere in the picture.
Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.
Regular Guest
Thanks for the replies. Here's a couple more pics. First one is a tank between the upstairs floor joists. I assume this is the expansion tank. The second is a better pic of the pumps. Looks to me that they are on the return. Is this a bad, and if so worth the cost to have them moved? The last pic is the only numbers I see on this thing but it's either a code from the company that installed it or a serial number from WM.
After posting this thread I was able to get a local HVAC contractor to come out and take a look at the setup. He recommended a 50 gallon WM indirect-fired heater as well as replacing the controllers for an aquastat controller. He said it would make the boiler controlled by the thermostat and not fire just because it dropped below the set temperature. I need to do some more research on this piece. I also asked him about the outdoor temp reset and he suggested it wasn't really necessary if you have an aquastat controller. Any additional thoughts/comments are appreciated.
Regular Guest
Did some research on WM's website and I believe I have a WTGO-4 based on the depth of the boiler (~17").
Professional Member*
have a heat load done before you get another boiler. that may save you more than anything will. get multiple quotes. an indirect is a better system than the tankless coil in the boiler. i do not care for them, i find alot of them to be inconsistant and tend to be leak prone. and that could cause other issues.
Regular Guest
We had 3 baseboards replaced before we moved in. They said it'd take 2-3 purges before most of the air is out. Right now it's quite loud for about 15 seconds when the pumps kick in. Plus, the location of the bubble is right above our couch in the TV room.Originally Posted by firecontrol
Professional Member*
it should be 90% purged the first time. then the autovent should take care of the rest. unless it is not set up right. if the air does not get removed you have a better chance of a line freezing or prv blowing off or even burning out a pump. thats not including what the oxygen will do to the system. i recommend getting a boiler pro to look at it, just my two cents.
Professional Member*
** Based on what I can tell from the pictures. **
Your expansion tank or an automatic air eliminator is where the air needs to get to to be removed. I'm suspecting that the expansion tank is connected to the top of the boiler in some fashion either directly or to the supply coming out. The only thing I see that looks like an auto air eliminator is located above the closest pump in the first picture.
The water returning to the boiler (with the air in it) is pulled through the pumps and the air is chopped up into what's called micro bubbles. Once the water enters the boiler it slows down and expands (for a lack of better way to explain it) and the air is expected to float to the top of the boiler and exit via the pipe to the expansion tank. Trouble is once the air is chopped up into micro bubbles this doesn't happen as easily.
One thing you can try is to run the boiler/pumps for as long a period as possible. The longer the water circulates at heating temperature the more chance of getting the air out. I'd suggest that you turn the thermostats down as low as you can possibly stand the temperature in the house over night. In the morning turn the thermostats up as far as they will go. This hopefully will cause the pumps to run for a few hours solid. The longer the water circulates at temperature the better chance even a poorly plumbed system will have to get the air out.
Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.
Regular Guest
That's the problem...I've had 5 different boiler techs (from the same company, who, incidentally, installed this boiler and have been maintaining it ever since) come out over the last few months for different things. I don't think there are any other HVAC companies that service residential oil-fed boilers in Northern VA.
Last edited by iptman; 01-04-2013 at 11:48 PM.
Professional Member*
i wish i could come down. you wouldn't want to see my diagnostic and fuel surcharge.lol. have you checked the map here on this site? maybe someone is close enough.
Regular Guest
The tank is directly connected to the top of the boiler. Thanks for explaining the micro bubbles. I'll see if the wife lets me try your suggestion...we'll see.
Regular Guest
I think I'm going to wait to see how much the gas run from the street (~180 ft) is going to be. I got the estimate back for installing the indirect-fired DWH and it was 3 times what I was thinking.
Right now I think my options are:
1. Have the indirect-fired water heater installed anyway, could be reused later with gas boiler.
2. Install an electric water heater, temporarily, until able to convert to gas (maybe 6 months to 2 years out).
3. Deal with what I got (who needs to save money on fuel oil or take more than an 8 minute hot shower right!).
4. Convert to a gas boiler
a. Install indirect-fired DWH, or
b. Install stand-alone gas DWH, or
c. Install tank-less gas DWH
5. Replace the very old central AC with a heat pump, install stand alone DWH (if electric then wouldn't have unknown additional cost to run gas lines)
a. Retain existing boiler for supplementary heat, or
b. Install heat pump/furnace hybrid, remove boiler and baseboards.
Am I missing any options? I'd love to hear opinions on what I should do. We're planning on being in this house for the long term so I'd base any decision on a 10+ year time frame and cost recuperation.
Thanks everyone for all the insight.
Regular Guest
Come on... Washington DC is beautiful this time of year! Yeah I called 2 of the 4 that are within 25 miles of the 22015 area code. One place said I'd need to have both a plumber and one of their HVAC people come out (assuming twice the service fee). The other, when I asked if they worked on oil-fired Weil-Mclain boilers acted like I just spoke Chinese over the phone so I thanked her and hung up. I may try the other two on Monday. I think these oil burners are rarer around here than a Republican in the White House.
Professional Member*
If you have an old school compression tank such as that, you will have air problems. With an open style tank it is imperative that you do NOT install good air elimination as you will remove the air from the loops, the air in your compression tank will dissolve into the water, flow through the system, be removed, and the next thing you know the air in the tank is gone and you have to room for expansion. Air for the air,,.., get rid of the compression tank, have a diaphragm style tank be installed along with a high quality air separator installed in the proper location in regards to your pumps and your air will be removed within an hour or so of runtime.
As for the boiler,,,, natural gas typically is the way to go and will require far less service over the years.
Were it me,, I would install a wall hung condensing boiler such as navian. . This will also give you an on demand water heater as well. Good luck
...
Professional Member*
The number one thing that should be on your list of options is to find another service company. From what you've explained the one you're using now may understand oil fired equipment, but they don't understand hot water heating systems.
Long term plans (10+ years) require information first and then life cost verses function decisions.
You're already doing the first part by gathering information. I would suggest a notebook/scrapbook to collect all the info. and any thoughts you have plus a segregated bookmark on your computer browser to save links that you find. This information and education will allow you to understand what your being told and what is being suggested when you make your decision on repairs or replacement.
The investment you are going to have to make is going to be a large one no matter what route you take. The advice I give customers is to think it through and then consider options that once the money is spent (whatever you spent it on) won't end up being taken out and replaced (thrown away) down the road when anything else is done.
At the moment your hot water is the issue that drove you to doing the research. Ok, you seem to be leaning towards an indirect fired hot water heater connected to your boiler as the better option. I agree. And yes, they are a big investment. But! If you do your homework and get one that is the correct size and one that has a lifetime warranty it's a one time investment for as long as you live in the house.
The addition of the indirect to the existing system is going to require modifications to the piping/pumps/controls at the boiler. This means to have it done correctly (and not have things thrown away or replaced later) you need to find a contractor that specializes in hydronic heating systems, because it sounds like the company you're using now thinks what you have is fine and working correctly. From your pictures I would basically take everything that you have there and redesign and install it in such a way that no matter what you do in the future, it's good to go. The oil boiler would remain with a few modifications.
The cost of the indirect and the modifications can be offset somewhat because your oil boiler will no longer have to stay hot 12 months out of the year as it does now to keep the DHW coil in it ready to go at a moments notice. The modifications could also end up saving you fuel costs due to better circulation and response to thermostat calls for heat.
Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.
Professional Member*
I'm with fire control, I'd gut the room and do it right. I just had a situation were a guy had a high Eff boiler piped about as bad as it gets, I gutted it, did primary secondary, spirovent in correct spot blah blah. End result they were so impressed at how well the house heats and the boiler didn't short cycle all day. They were glad to pay me let's say
Professional Member*
Hey fire control want to throw up? Here
Before
After
Professional Member*
How many gallons if oil so you use a year and what is your average cost per gallon? Also what is the installation cost to add natural gas to your home, and what is the cost per therm they will charge? We can give you a return on investment cost by switching. My thinking is that if the system needs to be repiped anyways and natural gas has a good return on investment then replacement may be a better option as that is the best time to repipe it..
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Regular Guest
We just moved in to the house in November so don't have any yearly figures. Luckily the tank was full when we bought the place. We filled up the tank in early December and the gauge shows just under half full right now. I paid 3.99/gallon. I'm waiting for the gas conversion contractor to get back to me to get an estimate for all that.
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