EFM WCB-24 domestic hot water coil gasket leaking

Greetings!

Last year I purchased a small 1200 sq/ft cape that came with an EFM WCB-24 hand fired boiler tied in line with the oil boiler. This week is the first time I've used it and after some trial and error, I've got it down pretty well and was able to heat the house for a few days on 100% coal.

This morning I let the fire burn out to give things a rest until it starts to stay colder out during the day, and now that the boiler has cooled down I notice the plate for the domestic hot water coil is weeping pretty badly around a few of the studs. It's bad enough that I see a drip to the floor every 30-45 seconds.

Poking at the exposed area of the gasket it's obvious that it has become brittle so I wonder if it's time to drain the boiler and replace it. Before I call EFM to see if a gasket is available (I hope so since the unit has apparently been put back into production), I am curious if anyone recommends I try to carefully "snug" the nuts up to slow the leak until the end of the season. My instinct is to not touch it since the gasket is so brittle I imagine odds are I'd only make the leak worse but perhaps others may disagree and have had luck doing this.

So what is the consensus, replace the gasket now or try to snug the nuts up and temporary slow/stop the leak?

Thanks!

Start soaking the nuts with pb blaster now and pickup 2 new gaskets, 1 to use and 1 for spare keep it in a cool dry place away from sun light. If you feel real brave you could try to tighen the nuts but if the gasket has hardened it will be a nogo and the studs may break. get your drills, taps and ez-out ready put some heat to them before you try to turn them. Good luck

crazy4coal wrote:Start soaking the nuts with pb blaster now and pickup 2 new gaskets, 1 to use and 1 for spare keep it in a cool dry place away from sun light. If you feel real brave you could try to tighen the nuts but if the gasket has hardened it will be a nogo and the studs may break. get your drills, taps and ez-out ready put some haet to them before you try to turn them. Good luck

Good advice above. Also some good info in this thread: Replacing Domestic Hot Water Coil Gasket

Thanks for the tips! Fortunately the nuts and studs are all in great shape so a quick shot with PB blaster and 15 minutes later I was able to loosen half a turn and re-tighten each of them one at a time with only a 3/8 ratchet.

The leak seams to have stopped (many of the nuts were pretty loose) so with some luck I can wait to change the gasket until the end of the heating season. I'll be sure to order two of them!

Out of curiosity is there a recommended torque to use to prevent warping?

I attached a picture...the dampness is the PB blaster.

When you do the gasket be sure you put never-sez on the studs. The nuts should be checked and tightened once a year as part of service.

Well from the look of things it hasn't been maintained very well. The firebrick looks OK but externally it could use some TLC and fresh paint. I'll be sure to use anti seize on the studs and probably add washers to ensure even clamping pressure.

The heat this thing makes is amazing, loaded with coal and even with the draft closed all the way the water would hover between 195-205 causing the aqua-stat to kick the circulator on every half hour to prevent boiling and that alone had the house at nearly 80 degrees! My thermostat never had a chance to call for heat.

So I think it's just too early to use it full time. Either that or I don't know what I'm doing yet.

That is a very nice boiler. Does it have a barometric draft control on the smoke pipe?

Nope, it doesn't. And my chimney comes up through the house so the draft is very strong once it gets warmed up. Should I add one even with the oil boiler on the same chimney?

Does the oil unit have a draft control installed? If so, you may want to adjust it to a lower draft setting.

W3DRK wrote:The heat this thing makes is amazing, loaded with coal and even with the draft closed all the way the water would hover between 195-205 causing the aqua-stat to kick the circulator on every half hour to prevent boiling and that alone had the house at nearly 80 degrees! My thermostat never had a chance to call for heat.

You might want to check the load door and ash pan gaskets for leaks.You don't want to keep dumping the water,sooner or later the PRV will blow

If the expansion tank is properly sized, 200 degrees should be fine. But yes, check the gasket on the ash door.

Hey Dennis, another Pottstown guy! I'm technically just barely in Boyertown but I've got a Pottstown address. Would you mind letting me know where the best place in the area is to buy coal? Just to get started I picked mine up in bags at Pottstown Roller Mills but I'm wondering if there are any better places.

Besides looking for obvious tears/fraying, is there any special way to check the gaskets?

The PRV is not purging and I assume the expansion tank is fine since the pressure seems to hover around 15 psi. The problem is if the circulation pump wouldn't occasionally kick in (EFM documentation says to set aqua-stat at 200F) the water temperature would eventually reach the point of boiling.

So assuming the gaskets are good I should expect to be able to maintain a steady water temperature of about 180F (again, according to EFM docs) on a 50 degree day without extinguishing the coal due to lack of air?

Dennis wrote:

W3DRK wrote:The heat this thing makes is amazing, loaded with coal and even with the draft closed all the way the water would hover between 195-205 causing the aqua-stat to kick the circulator on every half hour to prevent boiling and that alone had the house at nearly 80 degrees! My thermostat never had a chance to call for heat.

You might want to check the load door and ash pan gaskets for leaks.You don't want to keep dumping the water,sooner or later the PRV will blow

Rob, no draft control of any kind anywhere on the flue pipes.

Is this something I should consider installing?

Rob R. wrote:Does the oil unit have a draft control installed? If so, you may want to adjust it to a lower draft setting.

I think you would have an easier time keeping the boiler at the right temperature with a barometric draft control installed...especially on warm, windy days. I used to run a hand-fed boiler similar to your EFM, the brand was Itasca...anyway, it had the same temperature control with the chain that opens and closes the air inlet. On windy days it would dump heat frequently (I had a dump zone hooked up like you) because the strong draft would draw air around the inlet damper and up through the coal. A draft control on the smoke pipe really helped with that. Word of warning, if you put a baro on the smoke pipe you should cover it with foil if you plan to burn wood regularly. A chimney fire is a BAD thing anytime, but if you have a baro that can open and supply lots of oxygen to the chimney fire, it will be far worse.

W3DRK wrote:Hey Dennis, another Pottstown guy! I'm technically just barely in Boyertown but I've got a Pottstown address. Would you mind letting me know where the best place in the area is to buy coal? Just to get started I picked mine up in bags at Pottstown Roller Mills but I'm wondering if there are any better places.

I'm in Chester co./East Coventry.Roller Mills has Blashack bags and bulk and priced reasonable with a high lift truck.I get UAE straight from the breaker delivered at $240. ton,if intrested i'll give you a number.

I'd listen to Rob since he is more fimilar with your boiler,If the baro don't help keeping the temps. down then lower your aquastat to 150/160. That should keep the temps down and have enough heat

W3DRK wrote:Besides looking for obvious tears/fraying, is there any special way to check the gaskets?

put a dollar bill in the door and if it pulls out, then repalce the gaskets.
Krings Stove Shop is a great place,they should have gaskets if needed.