Water Temp and Lubrication

Hi,

I have an EFM DF 520 coal boiler. I have two questions:

1. I can set my L4006 Honeywell Aquastat at 240 degrees--its maximum setting. My water temp never gets above 140. I have the feed rate and air set for my house and my zone based on the charts. I tried to get the aquastat out of the well. It seems to be corroded in there. My plan is to remove the aquastat and replace it. Is this a good first step towards solving my water temp problem?

2. Is the set screw on the top of my blower/auger unit an oil fill hole? If it is, what is it lubricating, and what type of oil should I use?

Thanks,

Eric

When you say that your water temp never gets above 140*, does the stoker stop running at or near 140*? or in other words is the aquastat stuck at 140* regardless of the number you dial in?
Or, does the stoker run and run, and the water not exceed 140*? Burning lots of coal, but not raising the water above 140*?
What are your feed and air settings on the EFM stoker?
What is your chimney draft?
And how big of a house are you heating, how good are the windows and insulation?

Lots of variables here..

If you remove the aquastat housing, and the copper temp sensor won't come out of the 'well' in the
boiler, the probe is often surrounded with a heat-transfer compound.. it may need to be picked out with
an ice pick or piece of wire.

My boiler uses a Honeywell L8124A aquastat, are you sure the 4006 is the right model to use??

Greg L

Eric, you have posted about water temperature issues in the past. Have you made any changes since last winter? It would really help if you mapped out how your controls are wired, and explained the problem in more detail.

-Rob

Thanks for the replies. I'll try to answer all of your questions.
Greg--
1. The boiker shuts down at 140.
2. My feed rate is 6, and the air is 7. This should produce about 129,000 btu's.
3. My house is about 2400 square feet on three levels. The house has 5 year old thermopane windows. I have r-25 in the second floor ceiling and r-15 in the attic rafters.
4. My chimney is masonry. It is about 18 inches by 24 inches interior dimensions.
5. The 4006 is the one that was installed with the boiler 6 years ago.
Rob--
1. I have installed cast iron radiators on the second floor. The house is definitely warmer, even with the water temp only getting to 140.
2. I'm not sure that I can accurately map out my system. The thermostat wires run to two relays which control the circ pumps. The aquastat is wired to a switch box so that I can run on oil if necessary. That swtich box runs to either the oil gun or the blower/auger. I have two zones in the house; one for the first and second floor.
Thanks again--Eric

Eric, is the 4006 the only aquastat installed on your EFM? It only has a setpoint and differential...not my first choice to control the boiler.

I suspect a control problem...either due to something faulty or not hooked up correctly. Does it behave the same way with all zones?

-Rob

bleecker wrote: The 4006 is the one that was installed with the boiler 6 years ago.

Did the temperature ever make it above 140 in the last 6 years ? Was it heating before and now it's not ? Possably their is a Honeywell triple aquastat , with the 4006 as a second high limit cut-off ? 140 is to low a temperature to run, not as much energy and the boiler will condense and rust.

Thanks for the replies:
markviiii--
1. Yes. The 4006 is the only aquastat that is on the boiler. The upper limit is the set point and the lower limit is controlled by a differential setting that can be adjusted between 5 and 40.
2. It behaves the same way with all zones.
AA130Fireman:
1. Since installing the EFM DF 520, I have never hit 180.
2. Where would I look for another aquastat? I can only find one. Could another aquastat be inside the boiler?
Thanks again,
Eric

What brand of coal are you burning? Have you measured the draft to the boiler?
A L8124 triple aquastat will control the stoker much better then a 4006. Visit the Honeywell website, there are .pdf files for all the controls, read about them.

If you look on this picture the triple aquastat is the larger gray box to the left of where the yellow auger stops, the other aquastat is above the yellow auger in the middle.

Are those cable ties around the baro

I just notices this:

I can set my L4006 Honeywell Aquastat at 240 degrees--its maximum setting. My water temp never gets above 140.

The boiler shuts down at 140.

Looks like a control problem.

Yes, they are GONE. I wraped a piece of galvanized around the baro so all the stove pipe is double wall. I'm a little close to the ceiling and that was untill I had all the screws in place to hold while I drilled. Those were taken during the initall installation. They did NOT hold the baro on. I have 3 screws in all the joints.

That's what I figured. Nice job on the installation!

Wood'nCoal wrote: A L8124 triple aquastat will control the stoker much better then a 4006.

x2. A L7224 will also work, I installed one on my dad's EFM, and it runs excellent.

Before you start tearing out controls, study the wiring diagram in the EFM manual and make sure the rest of the system is wired properly.

Eric, was your boiler setup for steam before you got it? Also, where are you located?

-Rob

If you are using a regular aquastat to fire the boiler , it will only fire when it hits the low limit and will stop when it hits the ADJUSTABLE high (the differential) that you say is adjustable from 5 -40. When yous circulators are pushing your water is stone cold untill it tells the stoker to fire. A triple aquastat will fire before the low limit if their is a call for heat and maintain the low limit when their is no demand. It will also control the circulators from pushing cold water till the temp. catches up. IT'S like a truck pulling a load up hill, the driver needs to hit the GAS PETAL before the hill, if he hits it at the top it's too late.

L4006A breaks the circuit on a temperature rise to the
control setting. It is used for high limit or low limit control.
When used as a controller or as a low limit, a separate
high limit must be used.

L4006B makes the circuit on a temperature rise. It is
used as a circulator controller, delaying circulator
operation when boiler water temperature is below the
control setting.

Life would be easier if you used an L8124A or L7224A, but if you have an L4006A, I would set the limit at the high limit and that would be 180, which means you definitely need a mixing valve if you have a domestic water coil.