Two Questions per Hot-Humid Days

Two Questions per Hot-Humid Days

PostBy: chlop On: Fri Jul 26, 2013 5:04 pm

I've had my EFM 520 for about five years and I really like it especially in that I can heat my house for about @1200 a year. The only problems I encounter occur during hot and humid summer days when I sometimes experience outfires. This last week, the water temps were set at 170-190; the coal feed was at 3; and the air was at 4.5. The fire stayed lit during two of the three 90 degree days and then went out, and reigniting the boiler was difficult. Question 1: Is there any way to maintain a fire during extended days of heat/humidity?

When I was starting a fire, the boiler began to leak water around the domestic hot water gasket. As it turned out, one of the bolts was loose. Now, I'm having water drip from the pipe that drains the pressure release valve. I've drained the expansion tank. I reset the water temps at 140-170, as the weather is much cooler this week. Question 2: Why would the release valve be draining?
chlop
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF520

Re: Two Questions per Hot-Humid Days

PostBy: Rob R. On: Fri Jul 26, 2013 6:13 pm

chlop wrote:Question 1: Is there any way to maintain a fire during extended days of heat/humidity?


Yes. Use EFM's recommended settings that they have kindly provided in the manual. 200/160 on the aquastat, 2 minutes every half hour on the timer, 4 teeth & 4 air (maybe a little over 4 on the air...4.25-4.5 depending on the coal).

Your high and low limit settings are too close together, and your feed/air settings are probably not helping. What do you have the timer set at? Has the boiler and flue pipe been cleaned?

I have installed four different EFM 520's and none of them have ever experienced an outfire with EFM's recommended settings:

What is the pressure in the boiler? Should be roughly 12-18 psi. If your expansion tank was water logged, that probably caused the pressure relief valve to bleed off some water...it may have a piece of dirt that is preventing the valve from seating properly. Shut the boiler off and let it cool, put a bucket under the down-tube, and open the relief valve manually a few times to "flush" it. Monitor it for a while to see if it is still dripping...if it is, and the boiler pressure is correct, it is time to replace the relief valve.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: Two Questions per Hot-Humid Days

PostBy: lsayre On: Fri Jul 26, 2013 6:16 pm

If your DHW coil has a slow leak it will pressurize your boiler until it opens the relief valve.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

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Re: Two Questions per Hot-Humid Days

PostBy: chlop On: Fri Jul 26, 2013 6:32 pm

Thanks for responding so quickly... I had the boiler and flue pipe cleaned about a month ago, and the timer goes for two minutes every half hour. Right now, the pressure is at 30. Interesting that the manual would recommend 4 for the feed and
4.25 for the air. I had thought that my reducing the coal feed would conserve the fire.
chlop
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF520

Re: Two Questions per Hot-Humid Days

PostBy: Rob R. On: Fri Jul 26, 2013 6:38 pm

If the pressure is at 30, that is why your relief valve is leaking. Either the tankless coil is leaking, or the pressure reducing valve is malfunctioning.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: Two Questions per Hot-Humid Days

PostBy: chlop On: Fri Jul 26, 2013 6:41 pm

I'm just curious----is the pressure relief valve or the coil cheaper to replace?
chlop
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF520

Re: Two Questions per Hot-Humid Days

PostBy: coaledsweat On: Fri Jul 26, 2013 7:17 pm

chlop wrote:I'm just curious----is the pressure relief valve or the coil cheaper to replace?

The valve is cheaper than the coil. Shut the hot water feed off and bleed the pressure down to 12-14#. If the pressure rises again, it's the valve. If the pressure remains low, it's the HW coil.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

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