OIL USE and Burner setting

[Seasoned Oak]

100 PSI is the old standard. Newer modern oil burners operate at 140. That said nozzle specs are still calculated at 100 PSI. I would turn my aquastat settings way down in summer if your heating hot water with yur oil boiler. PS (not a very efficient use of oil) since the whole time in between water draws the boiler loses heat quickly up the flue. During the heating season water temps will depend on if your running finned baseboard or cast iron radiators and how many relative to Sq footage.

 

[antioil]

I agree that it is plausible that the previous tech set your unit to be less efficient. That is common practice in the name of 'fewer callbacks' from irate users. Whether that inefficiency was caused by a reduced pressure is impossible to say. As in our prior discussion, the techs do a number of different adjustments, to the oil flow rate (which depends on the oil pressure AND the nozzle used), the air flow rate, the aquastat temps, etc, all of which can impact the efficiency.

I just had an oil delivery and am now able to compare my "summer oil use" this year and last. Almost identical at one gallon per day from the last spring to September 19th. I was very surprised as the setting from 2015 was so much different, as I mentioned above. So now I'll look at the difference in the circulating pumps as all 3 are now new Grandfos pumps. I got a great deal on 2 of them as there is a rebate back to the distributor through Mass Save, the states energy saving program. Last winter I paid $80 dollars for one and just recently I paid $50 for 2.

Thanks all for your comments and be look out as the winter approaches for more comparisons. My hypothesis is now that the past increase in oil oil use was due to defective circulating pumps. We'll let the numbers do the talking.

 

[woodgeek]

I just had an oil delivery and am now able to compare my "summer oil use" this year and last. Almost identical at one gallon per day from the last spring to September 19th. I was very surprised as the setting from 2015 was so much different, as I mentioned above. So now I'll look at the difference in the circulating pumps as all 3 are now new Grandfos pumps. I got a great deal on 2 of them as there is a rebate back to the distributor through Mass Save, the states energy saving program. Last winter I paid $80 dollars for one and just recently I paid $50 for 2.

I would bet that its simply parasitic loss. Most boilers run 0.5-0.8 gallons/day in parasitic loss....why the boiler room is always so warm.
Maybe you used another 0.2 gallons/day to heat water from a tap.

One easy thing to check is for thermosiphons....go feel your radiators in the summer and see which are stone cold and which are slightly warm. If you have any of the latter, it is gravity driven flow (through/around the pump impeller) increasing your parasitic loss. I was losing another 0.5 gal/day from one loop during the summer (and heating that space). The solution....close a cutoff valve at the beginning of the summer, open it in the fall.

 

[maple1]

I'm not really seeing how 'bad' circs could cause more oil use?

 

[velvetfoot]

Me neither. Less electric use, yes.

 

[antioil]

There must be something about these water pumps to get the Commonwealth of Mass to subsidize them. They do have Low, medium, high and automatic settings. I assume it means just how fast the water flows.

I was told they will save on oil.

Is it possible that it speeds up the delivery of the hot water to the registers and therefore heats a space faster?

 

[maple1]

You didn't say exactly what kind of pump (circulator). And I don't know anything about Mass programs. But if they are Alpha pumps, they use significantly less electricity than conventional ones.

I would ask whoever told you they save on oil, exactly how they save on oil.

 

[antioil]

Grundfos Alpha variable speed.

Cannot ask that person as I got them at a plumbing supply house but I will do an internet search.
Just a home owner not a pro. Yes there is an improved electricity use but they also said oil use.

Just a guess but if a zone called for heat and these pumps increase the speed to get the hot water flowing wouldn't a zone get warmer faster?

 

[antioil]

I found this at a site:

"These variable-speed, ECM circulators make a lot of sense for several reasons. One, they allow you to save pumping energy by varying the flow rate. Two, by reducing the flow they can increase the temperature difference between water leaving the boiler and water returning--which improves efficiency, so you use less heating fuel. (With a condensing boiler, this higher delta-T allows the boiler to truly operate in a condensing mode during swing seasons when less heat is being extracted out of the hydronic loop; often during those seasons, boilers stop operating in the condensing mode and their efficiency drops about 8%.) And three, these pumps compensate for the fact that circulator pumps are almost always significantly oversized."

It also mentions savings on electricity also. They are expensive but it cost me just $25 because of the Mass Save program and I didn't need to do anything like paperwork associated with a mail in rebate.

What do you think?

 

[woodgeek]

I think "Do you have a condensing boiler?"

 

[antioil]

I have a "typical" oil burner and a Turnham Boiler. I couldn't tell you what a condensing boiler is. I thought the reference to the savings in the snippet I copied would apply. Hey don't get me wrong I'm not working for any company here.

A broken pump has to affect oil use ! as the area needing the heat isn't getting it and the thermostat isn't rising and therefore the burner runs longer...right?

 

[maple1]

The burner only keeps the boiler hot. So if the house isn't heating and drawing heat from the boiler, the burner will shut down when the boiler gets hot. The burner can't see where or if heat is going where it's supposed to. The burner would actually run shorter with no water moving due to a broken pump.

 

[woodgeek]

Indeed. If no heat is being delivered, then the boiler shuts off and no oil is being burned.

A condensing boiler runs the water at a lower temp to be more efficient. The problem is that the oil combustion exhaust contains enough water that below some exhaust temp the water condenses on the heat exchanger. So, in a condensing boiler the exchanged is corrosion proof (like stainless) and there is a pump to deal with the condensate. If such a boiler is not set up right (like the wrong circulator pump or controller settings) then these savings are not realized.

It sounds like you have a standard (dumb) boiler where this is not an issue. On the bright side, the ECM circulators do use less electricity.

 

[velvetfoot]

I wish my insert had an ECM blower!