New OWB install, suggestions and advice

[tabner]

In some of the photos it looks like three pipes run into the back of the aquastat, but they don't, only one does. Two of them are the cold and hot running into the DHW coil. The one that does connect the aquastat is like a 4" long 3/4 piece of pipe, not sure if there's water in it, or if it's just a mounting bracket.
Two wires come off the aquastat, one runs down to the burner, one runs up to a small gray box overhead which has all the thermostat wires (from around the house) run into it as well as wires to the circulator pumps. So i'm guessing that is some kind of control box or something.
Anyways, it looks like the temp readings for the aquastat must come from inside the boiler, somewhere in the vicinity of the DHW Coil - i'm assuming this since it's basically the only place the aquastat is in contact with the boiler.

 

[Fred61]

There is a capillary tube on the back of the aquastat inserted into a dry well screwed into the boiler. Go to Youtube and search the part # on the inside of the cover. I think there's a description of the unit.

 

[maple1]

I would just do as I mentioned above. Verify the temp gauge is correct then just adjust the aquastat accordingly. That stat is in a well. Could be that it wasn't done right so might not be sensing right.

 

[leon]

Hello tabner,


The only way to verify if the temperature and pressure gauge is correct is to shut down the boiler and let it cool and then drain the boiler down and remove the gauge. After that you will need to boiler water in a pot and using an oven mitt hold the probe in the hot water keeping it in the water and not touching the base of the pot.

Your Burnham boiler most likely has several side tappings for the steam chest and the thermocouple well to allow it to be used for both steam and hot water.

The Honeywell triple aquastat is set up so the copper coated thermocouple probe is directly attached to the control like mine and it exits the
rear of the triple aquastat and the copper coated thermocouple wire and probe enter the probe well from the rear of the triple aquastat like mine does.
The Honeywell triple aquastat has a clamping connection that permits it to be attached to the probe well using a screw driver to tighten the connecting clamps screw. The copper coated probe wire coming from the rear of the triple aquastat is short in length and that is why the clamp is needed to hold the triple aquastat in place.

The thing that none of use knows right now is whether the Honeywell conductivity paste was used in the thermocouple well. The highly conductive paste makes the probe well much more sensitive(conductive) to temperature variations to assure the control that the water temperature in the steam chest is accurate.

A theromocouple well will go anywhere there is a 3/4 inch National Pipe Thread tapping or reducer bushing in a larger TEE that will accept the bronze probe well.

 

[tabner]

Thanks all.
So what are my best options here? Basically i need to confirm what the temp of the water going out and coming back is. i'm going to try again tonight to get a better reading with a thermometer i have on the outlet pipe. I know someone said IR thermometer, but it won't read on the copper pipe i don't think. If i take a meat thermometer, and wrap it snug up against the outlet pipe, how accurate of a reading do you think i'm getting? Water inside the pipe probably a couple degrees hotter than the exterior reading?

 

[leon]

What Model Burnham Boiler is this??????????????????????

All I am going to do is groan here as apparently the plumber installed the triple aquastat in the domestic coil ports~!!
If the unit did not come with a coil and there is simply a gasketed flange plate that is OK BUT that is not the correct way to do this installation.

Invest in a IR gun from Harbor Freight or amazon and check the pipes temperature at the inlet of the circulator and the cool water return line to the boiler sump.

 

[tabner]

I just ordered a hand-held IR thermometer from amazon - i'll update in 2 or 3 days with my inlet and outlet temps.

In the meantime - not to change the subject, but can anyone speak to the quality of HeatMaster vs Central Boiler?
My research suggests that the Heatmaster (G100) is better quality, however the Central (Edge 350) is 2k cheaper, and the dealer is in state. Big difference for me is the Heatmaster dealer is out of state and won't work on my install because he's not insured here. Whereas the Central dealer can get me up and running correctly before they leave.

 

[maple1]

Thanks all.
So what are my best options here? Basically i need to confirm what the temp of the water going out and coming back is. i'm going to try again tonight to get a better reading with a thermometer i have on the outlet pipe. I know someone said IR thermometer, but it won't read on the copper pipe i don't think. If i take a meat thermometer, and wrap it snug up against the outlet pipe, how accurate of a reading do you think i'm getting? Water inside the pipe probably a couple degrees hotter than the exterior reading?

IR gun. Spray shiney stuff (copper) first with a shot of flat black spray paint.

You might get a good reading with the meat thermometer if you can get it flat against the pipe & wrap some pipe insulation around it.

You don't need to remove the boiler thermometer to check it. Just shoot the fitting it is in with the IR gun. Will be very close.

 

[maple1]

The thing that none of use knows right now is whether the Honeywell conductivity paste was used in the thermocouple well.

A good point.

If there is enough give to the wires, the aquastat & its probe could be pulled out of the well to check its health. Most times there isn't enough play. In which case though, you'd just need to unhook some wires then hook them back up again.

But be careful - the probe/bulb is kind of delicate.

 

[E Yoder]

I just ordered a hand-held IR thermometer from amazon - i'll update in 2 or 3 days with my inlet and outlet temps.

In the meantime - not to change the subject, but can anyone speak to the quality of HeatMaster vs Central Boiler?
My research suggests that the Heatmaster (G100) is better quality, however the Central (Edge 350) is 2k cheaper, and the dealer is in state. Big difference for me is the Heatmaster dealer is out of state and won't work on my install because he's not insured here. Whereas the Central dealer can get me up and running correctly before they leave.

If price is an issue the GS100 is nearly $1000 cheaper and nearly identical to the G100. GS models don't have a smoke bypass or viewing glass for the reburn (comparing to G). Both all stainless firebox and water jacket.

 

[maple1]

More semi-informed input on the location of the aquastat, and the DHW coil.

A DHW coil in an oil boiler has to be about the most expensive & inefficient way to heat DHW there is, in the off-heating season. I had one for 17 years. Wondering what your summer time oil bills are? That's more for curiosity.

But seems to me that the location of the aquatstat has in this case been optimized for DHW production. And not the house heating aspect. With no consideration to how much oil is used. When heating DHW in the summer, the cold DHW coming into & through the coil will quickly cool off the boiler water immediately surrounding the coil. Because the boiler water isn't moving. It is just sitting there. So the stat senses that, and turns the oil burner on. Which is close to the coil. But not immediately under it. Water around the coil gets hot, coil gets hot, burner shuts off. All the time that is going on, water gets & stays hot at the top of the boiler. Which does nothing to heat the coil, but does serve to send a lot of heat up the chimney. Major stand by heat loss. Very much especially if the 190 boiler temp is what you see in the summer also.

This might also be affecting heating operation. Whenever DHW is used, the oil burner kicks on, since the stat is right next to it. Even though temp at top of boiler might not need the burner on right then. Meaning the stat isn't controlling the overall boiler temp very well. It is just controlling the temp of the water, right at the DHW coil.

All that would be moot, if there was good constant internal boiler circulation, or when DHW was being used. There would be some, when the zones are circulating. But not sure how flow through the boiler from that, is affecting the immediate coil area.

What I would be thinking of doing to try to improve on all that, while adding an OWB on, and if I still wanted to heat DHW with this oil boiler in the summer, is move the current stat to a well in the top of the oil boiler, and putting a new separate smaller one where the current one is, that controls only a separate circulator. That circulator would either be in the new proposed flat plate HX oil-side loop, or a new separate small bypass loop all together that circulates from the top of the oil boiler directly to the bottom of it, making flow that would go through the area of the DHW coil. The new HX loop could maybe serve that purpose also (oil boiler internal circulation in the summer), but would need an additional control added so it would also turn the circ on, when the OWB is running & sending heat to the flat plate.

If I wasn't going to add an OWB & still wanted to use the oil boiler for DHW, I think I would still consider adding the bypass loop, & extra stat & circ, and moving the existing one. That way you could lower overall boiler temp. The new loop would circulate boiler water around/through the DHW coil when needed until it cools to the point of needing more heat. Then the existing stat kicks in & does its thing with the burner.

Another option would be to not use the oil boiler at all for summer DHW and add a simple electric tank heater for it. But not sure it could stand going cold for the whole summer. Some don't take it well. (Assuming this isn't a cold start boiler).

 

[tabner]

Thanks Maple1. I burn a little over 3 tanks of oil per year, roughly i would say 2 to get me through winter (about 4-5 months in CT) and then another tank to heat hot water through the rest of the year. In addition to the inefficiencies you just listed, i also hate the DHW in the summer because my house is naturally hot, and i don't have central air. I know it's not much, but that boiler sitting close to 200 degrees at all times is like a little heater unit in my finished basement. But i asked my plumber about switching to a hybrid electric hot water for the summer months, and he really pushed me away from it because as you mentioned, the oil boiler cooling down all summer is a recipe for disaster, he said, as far as seals and gaskets and leaks.

as far as water temperature, i got the IR gun in, and it does look like the water flowing on the outlet of my zones is close to or over 200 degrees. the temp kind of fluctuates depending on whether i'm shooting the black fitting, or the copper, etc, but it reads anywhere from 190 to 205. And then when i shoot down through a gap in the boiler jacket, to hit the actual cast iron body of the boiler, i'm getting 200 to 210.

I do generally turn the boiler temp down in the summer, to save oil, since i'm not heating the house. But i'm now wondering how accurate my aquastat is. Not to mention it's currently set at something like 140 Lo and 180 Hi, i can't dial it down much farther before you bottom out the range that's even an option on the aquastat.

 

[maple1]

Pic in post 18 looks like settings at 145/165? I would not have it at 180 hi. More like 140/160.

Your aquastat itself is likely accurate, it's just that it's probably not situated in a very good place. And maybe also doesn't have any heat sink paste in the well - which may or may not be making a difference. My stat on my old boiler was also at the same spot as my DHW coil, on the side. But it was also right above the burner, kind of sandwiched between DHW coil on the back of the boiler & burner on the front. My boiler also had a bypass loop with separate aquastat. It was a pig on oil, just heating DHW, it has the stats turned down as far as they could go while still making just useable DHW.

IR guns can be flaky when trying to measure pipe temps. Some of that can be taken care of with flat black spray paint, but I had mine out a couple weeks ago playing with it & it was still all over the place when shooting pipes. Except for the flu pipe, it was rock solid with that. Could be my IR gun isn't a very good one.

 

[salecker]

i also hate the DHW in the summer because my house is naturally hot, and i don't have central air. I know it's not much, but that boiler sitting close to 200 degrees at all times is like a little heater unit in my finished basement. But i asked my plumber about switching to a hybrid electric hot water for the summer months, and he really pushed me away from it because as you mentioned, the oil boiler cooling down all summer is a recipe for disaster, he said, as far as seals and gaskets and leaks.

[/QUOT
I would go with a water heater and not look back.
My backup oil boiler sits most of the time cold,at room temp in my boiler building.
It was a used oil boiler,and has been a backup for 9 yrs now.Spring and Fall it gets used,and once in a while in the winter if i don't get home in time to recharge storage. Sometimes more than others.No problems with leaks.
All my DHW is electric,eventually that may change,but i am sure it is cheaper than running a oil boiler for the summer for DHW

 

[Fred61]

Using the average price for fuel oil around here a full tank would be about $700.00. That's a lot to pay for a summer's worth of hot water. Get yourself an electric or hybrid water heater and you will bring that total down to $200.00 or less unless you are using hot water for some industrial process in your garage. Turn off the boiler and exercise it for a few minutes each week. I have a cold start peerless with a superstore but in the summer I heat the Superstore with a Nyle heat pump. I exercise my boiler on "wash" day which helps to keep up with the huge draw of hot water that our extra large
washing machine slurps up. My wife believes that clothes will not come out clean unless the water is scalding hot.

 

[maple1]

When my old boiler went cold, it leaked a bit but it wasn't a structural thing. It leaked around the (old) coil gasket.

Our DHW with an ordinary tank electric heater runs us about $25/mo. - should have made the switch long before I did. And, the old boiler also added to the summer heat in the house.

 

[tabner]

if i'm going to install an OWB doesn't it make more sense to leave the DHW on the oil boiler though? Since that way i'll be heating my house and my water with the wood?

 

[maple1]

if i'm going to install an OWB doesn't it make more sense to leave the DHW on the oil boiler though? Since that way i'll be heating my house and my water with the wood?

Maybe. Half the year your OWB wouldn't be burning though. (Well, some burn all year round but I definitely wouldn't). So you'd have to weigh heating season vs. non-heating season benefits vs. disadvantages.

I use a flat plate HX to heat up our electric tank heater when burning wood. If/when the fire goes out for a few days, the elements automatically kick in.

It might ultimately come down to how your oil boiler would handle going cold though. There's only one way to know for sure, that's let it go cold & see what happens. I suspect most would to OK. Mine only had one gasket area, that was the coil gasket.They can be replaced when they need to be. Might require some cutting & resoldering of pipes but otherwise not that bad. I didn't have any issue with any leaks otherwise. No guarantees in anything though.

 

[salecker]

if i'm going to install an OWB doesn't it make more sense to leave the DHW on the oil boiler though? Since that way i'll be heating my house and my water with the wood?

Only if you have extra money that you don't really want.Think of the 6 months or even 4 months that you have the oil boiler running to maintain temp for DHW.Plus think of the extra heat in your house on those hot summer days.