L8124

Techman

Hi Tim.Could you give rough dimention of the boiler being hugged. This is like dancing ,how do I hold my arms??
BTW,my apprentist and I are reading/studying your book "Hydronic Controls",VERY GOOD!

Joseph Miller

L8124

I have a old boiler with a L8124 relay. I have recently installed a seperate hot water heater. I would like to disconnect, if possible?, the low limit and control the boiler with only the t-stat. Since I will be heating mostly with wood,I want to try to eliminate the boiler maintaining temperature when not in use during the day.

Thanks for the reply...Very much appreciated

Leo_15

Depends

If the boiler is old as you say, turning it off could lead to the seals leaking. First if it hasn't been done be sure it is cleaned real well, the reason, turning it off or making it cold will lead to moisture. Moisture mixes with the products of combustion to cause an ugly mess. Depending on your boiler some are more forgiving than others. Lastly before turning it off try turning the low limit to the lowest setting. An indirect water heater would have kept the boiler from running all the time but kept it warm, but that's too late now.

Leo

Joseph Miller

Thanks for the reply Leo...

The boiler is an old Weil Mclein with a tankless coil. After installing a new HW heater I turned the low limit down as far as it goes and the boiler still maintains ~140 degrees. It just seems to me this is wasting fuel oil.

However, I do not want to cause more problems with the seals leaking.

Do you know if it is possible to eliminate the low limit on the L8124?

Thanks again...

Paul Fredricks_8

I would just turn it down to a spot where it maintains about 90 or 100. I know it's not marked that low, but you can probably figure out where to set it. The idea is to keep the boiler from getting cold.

bill_97

I agree with Leo and Paul

Turn the low limit down as far as it will go and set the differential as high as it will go .

The 8124 can be made to be cold start , but with an old boiler I wouldn't risk the leaks , and if you rewire the control I'm not sure what that does with the liability if something bad happens .

If that wasn't a problem and you had an indirect heater connected to it , then I would say go for it !

Unknown

Joseph have your contractor

(a professional not homeowner)do the following:

Remove the wire from the "B" terminal on the R-W-B side and place a jumper across R and W. This will disconnect the low limit side and make the L8124 relay a high limit only relay solving your problem.

With that said you boiler is now a cold start boiler and depending on water content may not work as well on the heating side due to starting at a lower temperature on a call for heat. It depends on the size of the boiler and how much water content in the system. The old timers had what they called a "Hug Rule" it was if you can't get your arms around the front of the boiler do not disconnect the low limit/domestic feature.

Leo_15

Tim

Your theory works but in this case he has a Weil Mclain boiler. I service way too many boilers annually and find that Weil Mclain and Peerless Jot& TW are the worst for plugging when left cold. The best alternative to this is get the boiler cleaned at the end of the heating season and run it for 15 minutes weekly. It is amazing how many people leave for vacation in these days of high fuel costs only to return and turn on a now plugged boiler. Was the fuel savings offset by the service call?

Leo

Unknown

Leo he already

has said that he is mostly heating with wood so it is already going to be shut off alot of the time.I do not like cold start applications never have and never wiil. This day and age with wood and pellets equipment is going to have a lot of down time. Hey I burn pellets about 75% of the time myself.

Joseph Miller

Thank you all for the information. I appreciate everyones time.

I have turned the low limit down as far as it will go, but the boiler temerature is still at 140. I wish I could keep it around 100.

Thanks again and have a good weekend....

Unknown

Hugging Boilers

is a wonderful pastime we all should participate in.

You stand in front of the boiler and place your left hand on the right hand side of your favorite boiler as it is looking at you. Then spread your feet and place your right hand on her (the boiler) left hand side, move gently with both hands gripping slightly the edges if you can do this it is okay to disconnect a dometic relationship with her (the boiler) If not then a personal domestic relationship will be required for many more years. At least if not a dometic relations ship a less intimate (low limit) requirement for comfortable years together. I hope that helps those too timid to hug her (the boiler.)

bob young

new single setting control

install a new aquastat . problem solved what could be easier . cheap too. the existing one could go any time too because it it is old.

Robert O'Brien

Doesn't

it really point out the obsolescence of a boiler that must maintain some temp 24/7/365? Is this a viable approach in 2008?

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Matthew Grallert

Get rid of that control Its using a pile of fuel for no good reason the indirect will keep the boiler dry and if it leaks well it is a WM