Tim

TonyS

There is a thread on the main wall...TT Prestige,sealed combustion. Could you look at it and give us your thoughts? Thanks

BoilerBuddy

New Boiler - condensing but not a condensing boiler~!

Had a new boiler installed a few weeks ago. Weil Gold CGA-5 140000 btu), It is now down to 10 degree F and it keeps up well, but company that installed had calculated to use a CGA-4. (105000btu) -

Thought there was a leak, but appears is condensing and coming down the chimney. Not lined. Have expensive quotes and scheduled to line after the holiday. it is pooling on the floor at times. especially in the morning. Is this dangerous?

The boiler seems to short cycle, comes on just under 3 min. then shuts off, circulator runs awhile longer. Does not heat up above 160 degree as Is controlled with Honeywell auto controller that has outside temp probe, also has auto damper.

Do you think the boiler is oversized causing these problems? Could the controller be causing the problems? Should I insist the boiler be replaced?

BoilerBuddy

condensing --- but not a condensing boiler!

From what Ive read, venting is needed, but not sure the boiler is running a hot enough temp.. 160max

what if after expensive chimney reline, it still has condensing problem, is this common problem that can be solved or am I in deep trouble? 

Is the Honeywell control unit keeping the boiler from heating up properly?

 Is the boiler too large for 1200SFT house..with 100 feet radiation.?

Tim McElwain

Boiler Buddy

the low set point temperature of 160 degrees seem to be very low. Typically with a baseboard system you want to run at 180 or higher. That with a 20 degree delta T (temperature difference) will not cause condensation. Add to that the fact that this is an unlined chimney it will surely condense.



Was a heat loss done on your house by the contractor who installed the boiler? If not I would insist he does one to determine if the CGA 5 is too large. That will cause short cycling as you are firing at a rate perhaps well above what is needed.



What is the number of the Honeywell Control? It sounds like it is using an outdoor sensor to set temperature perimeters.



Last question , why was the wrong boiler installed?

Tim McElwain

Using 600 degrees per linear

foot the amount of radiation at 100 feet would be 60,000 BTU's. We must however take other things into consideration such as size of pipe, circulator size etc.



The 60,000 BTU's should match up to the heat loss of the house.

Unknown

Gee,,,

Sounds kinda "familiar" right BoilerBuddy?

BoilerBuddy

condensing --- but not a condensing boiler!

The controller for the Weil CGA-5 bolier is a Honeywell AQ25142B Aquatrol Boiler Reset Control Panel with DHW priority for 4 zones, though I have only one zone.The boiler was "ordered wrong" from his supplier by the installer, he was to have ordered a CGA-4 boiler. Didn't notice until was installed. The limit setting on the the boiler is 160, should I move it to 180 ?  It is controlled by the Honeywell controller and not sure how to check the settings on it.The installer did not do a heat loss calculation. Said he has done hundreds of these replacements in houses similar to mine. Single story ranch with basement.

BoilerBuddy

condensing --- but not a condensing boiler!

The baseboard heating is 1/2" dia. metal tubing. BG NRF22 circulator. Installer now asking if I want him to derate the boiler, by blocking off burners?!

Unknown

Don`t do it,,,

Blocking-off burners is NOT the solution,,, your CO & access air will go NUTS!

Tim McElwain

Dave is right

derating is not a good thing as it can affect the efficiency of the combustion process.



You need to get the boiler temperature up around 180 degrees, that with the relining may help to eliminate the condensing. Your return water to the boiler is probably at times getting below 140 degrees and that is right at the point were condensing starts. Your installer also needs to do a combustion analysis to insure maximum operating efficiency on the combustion side.

BoilerBuddy

Condensing, but not a condensing boiler! Help!

Well, over a grand and relining of chimney complete, but still getting some condensation it appears.

My new Honeywell controller seems to keep the high temp under 160 and I would like to see it at around 180 as suggested. Problem: I don't know how to set the limit to 180 on the controller... HoneywellAquastat. The provided instructions given are for the typical "homeowner", and not showing how to set the limits....any ideas?

Mark Eatherton

Hood dilution air causing condensation in flue.

Is there a properly adjusted barometric damper on this boiler? If no, get a qualified contractor to install one, and block off the existing draft relief hood and all your problems SHOULD go away.



What is happening is the flue gases are being cooled off by the fixed draft relief hood, and the flue gas is cooling down below the condensation point. Installing a good barometric draft regulator will allow only the air necessary to maintain a good draft and eliminate the excess air being drawn up the chimney.



Make certain that roll out switches are installed at the baros opening to avoid the possibility of back drafting causing spillage of products of combustion.



ME

Tim McElwain

What is the model

number of the Honeywell Aquastat?

BoilerBuddy

Condensing, but not a condensing boiler!

Weil CGA-5 boiler and a Honeywell AQ25142B Aquatrol Boiler Reset Control Panel - I only have one zone loop.

Tim McElwain

The AQ25142B

can be set on the high limit to 190 Degrees, Low Limit to 150 degrees. The boiler differential is 2 to 41 degrees. The WWSD (Warn Weather Shutdown) 70 degrees. The boiler design temp is 180 degrees and the minimum return temp is 140 degrees. I think your control needs to be reprogrammed. If you do not know how to do that then get hold off a professional or contact your Honeywell rep.