buderus logomatic

Bluenose_21

I'm servicing two ge615 buderus boilers with logomatic controls. My problem is that the logomatics shuts down the indirect circ before it ever reaches temp.I set it for 120, it goes to 115. If I set it for 135 it goes to 129.What's up with this? Any help would be appreciated.

S Ebels

Have you

Checked actual tank temp vs. what the display is reading?

Make sure the sensor is in all the way and in good contact with the well.

Is it a Buderus indirect?

Bluenose_21

tank temp

The tank is a 500 gal storage with sidearm /rapfast heater.Sensor is in a dry well in the middle(end) of tank.Water from the top of tank is approx 10 degrees higher than display is reading. But doesn't the display show what the control(logomatic) thinks the tank is?

S Ebels

Make sure

The sensor is in good contact with the well. You have to remember that the sensor is electronic not hydraulic cap tube type. If it's flopping around in an oversized well it will give false readings. Try filling the well with some heat conductive paste and see what happens. Buderus also has specs on what specific resistance the sensor should read at a given temp. If it doesn't match those you could have a faulty sensor. Also with that size of a tank you are going to get some noticeable variation of temps within the tank itself unless it is constantly circulated.

Mark Eatherton1

The control is smarter than you think it is...

I used to get irritated at the same thing. THe boiler would shut down before its temperature reached 180 degrees, and before the tank reached it's set point. Then, I sat back and watched, and to my amazement, the tank "coasted" up to its set point. The logic can "see" rate of recovery and knows how much energy it has that can be transfered without having the flame rolling. Look a little closer and I think you'll find that the tank coasts up to its set point. No waste, just whats necessary. It also learns over time and adapts accordingly.

ME

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dconnors

Good answer Mark

always nice to know there are those that pay attention. Good Job

Joe@buderus

Mark's answer

Right on the button - it's the "Fuzzy" logic of the Logamtic Control. Thanks Mark!!

Bluenose_21

foggy

Is there no way to override the logic?I think that the fuzzy logic is alittle foggy.I realize that the boiler temp coasts up to its set point but the dhw never reaches temp.The only time it has reached temp is when I switched the control to manual and let rip for a few hours.If left on auto it goes to where it wants then waits for a drop in temp to start the pump again.This is a 100 unit apartment building, has a major draw from the tank first thing in the morning.It has continuous recirc. Tenants and super are not impressed with the cooler water.Tenants complain to super, super complains to me, I scratch my head,these are my first experience with the logomatic controls.These are replacement boilers, the hot water used to be control by a aquastat, in the same well, set between 130-140.

Paul Pollets

Priority??

Is the DHWtank set for priority zoning? Or are the heating pumps on at the same time?

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ScottMP

Blue nose

Check the thermister to make sure it is correctly reading the tank. You may have a bad sensor. Steves right , you should check the resistance.

Marks correct about the fuxxy logic, but what I here you saying is that it Never reachs the set point. Is that correct ?

Where do you have the recirc line connected ?

I would believe the control should read very close to what the real tank temp is, but where are you reading the tank temp from ? You mentioned that the tank is hotter at the top which would happen in that large a tank, due to stratification.

Are you reading the temp at an outlet faucet ? You would lose alot of temp as it travels thru the building piping.

Scott



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Darin Cook_3

WARNING! VERY IMPORTANT!!!!!!!

DO NOT EVER PUSH THE CHIMNEY SWEEP MAN BUTTON ON THE 2107 !!!!!!!!!!!

Once you awaken him - there is no stopping him.
He does not sleep.
He does not eat.
He does not rest.
He never stops looking for Sarah Connor, I mean the hydronic trash home owner.
He will rip the condemned boiler out and throw it in the street.
Your neighbors will be forced out in the street to laugh at you.


PLEASE NEVER PRESS THAT BUTTON!!!!!!!!







Darin

Wayco Wayne_2

What the heck????

I've never pushed that button, but now I want too. It's Just like telling a kid never to put beans in his ears. It probably wouldn't of occured to me to push it. Now I want to call my last Buderus install and make up an excuse to do so. Ack! Must... resist..... temptation. Good thing I'm leaving for Wetstock today. Maybe I'll forget before I come back. BTW what is that button supposed to do? WW

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Bluenose_24

temp

Scott, It won't reach the set point.The only time it did was when I switched it to manual.The recirc is into the bottom of the tank at the opposite end from sensor.I read the temp from relief valve(thank God for floor drains).I am going to test the sensor tomorrow.But the only thing I can't get my head around is that the if the sensor/thermister is bad,where does the control get the number that is showing me(ie. DHW temp.)?Isn't it what it is sensing in the tank?

kevin coppinger_4

kinda sounds...

like something from Dr Seuss...kpc

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Bluenose_24

Paul

Dhw priority?Hmmmmmmh?I have to check. The circs run 24/7 for heating.I know that when not calling for domestic that the boilers are dropping way down in temp and with a call for domestic they ramp right up to 180.Without DHW priority how would it act?

dconnors

Pushing the Chimney Sweep Button

The button is there so the burner tech can do a test without having to turn up the TStat. It also will alert us that you are playing with our equipment(joking).

Bluenose_24

Big brother Buderus

So that's why, I thought it was like a direct like to tech support or that a chimney sweep was on the way to slap my hand. lol

ScottMP

Daaaarrrrrin

How do You Know that ???

hhhmmmmmmm ??

Scott

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