Baxi HT 380

Joe_

Looks for those who may have installed this system. Just 3 weeks ago we had one installed to run our forced hot water and DHM as well as radiant floors. 4 zones all together. This is the first Baxi this installer had put in. We were told the Baxi rep would be here while the install was going on but that did not happen. The system seems to be doing fine, no issues besides a little water temp fluctuation in the shower.  Is there anyway to know how efficient the system is running? What could be causing the temp fluctuation and show I have installed the out door temp sensor for 130 dollars? 



Thanks you,

Joe

Al Letellier_21

BAXI

Great little unit and have installed a few but ALWAYS have the rep or supply house support guy come to make sure unit is set up properly. That little control set up device is so diffferent from everything else that until you do a lot of them, it's hard to make sure you are getting it right...call and bug the guy until he shows up or start selling something else....that should wake him up !!

Joe_

Al

Thank you for your reply.  The rep told our installer that the controller has been causing issues and to remove. The system has been working fine with no real issues but the DHW temp can get very high even though it was set to the 120. I put a thermometer to it and it read 136.  Also with 3.9 gpm we notice a significant drop in water pressure when showering and then just turning on the kitchen water faucet (hot water). The shower head is 2.5gpm. Also should we have an expansion tank on this system? One was never installed.



Thank you.

TFL

BAXI HT 380

Joe,

It is not a requirement have a distributor / manufacturer rep on site "during" your installation.  This service is generally offered to ensure that the homeowner (you) are thrilled with your new system and to provide support to installers that request it.  Based on your concerns, you should contact your installer immediately and have him bring in some support



.

DHW - The domestic hot water should have no perceptible fluctuation.  the boiler achieves the target dhw output temperature through modulation of gas input / hydronic water temperature.  The boiler's domestic hot water temperature variance should never exceed +/- one degree Fahrenheit which is imperceptible to the human touch.  Wide temperature fluctuations suggest that the unit either has gas supply pressures outside of manufacturer's requirements / limitations OR the unit was not properly commissioned with the use of a combustion analyzer





PRESSURE DROP - The Baxi HT uses a flat-plate heat exchanger to heat the incoming cold water.  The domestic side of the system will allow only the rated flow of water to pass through the unit.  That said, the GPM's passing through the unit are relative to the amount of domestic water pressure available upstream of the boiler and/or the draw downstream of the boiler.  Water will always travel the path of least resistance.  If you open a kitchen faucet and that is the path of least resistance (because it is closer or a shorter route to the kitchen than an upstairs bathroom, etc.) then the available GPM's / pressure is split between the two fixtures.  A tank style water heater for example, is a wide open vessel of water and offers little to no pressure drop (usually about 1 psi).  Again, with some simple investigation and perhaps a little plumbing from your plumber, it is possible to mitigate this issue.  3.9 GPM is the maximum rating of the unit provided the water pressure / volume is available to it.  A closer look at your plumbing could possibly rectify this.





EXPANSION TANK - The Baxi HT380 includes an integral expansion tank that should be adequate for the average home (30 USG of system volume).



 

EFFICIENCY - There are essentially two types of efficiency; combustion and system. 

With regard to combustion efficiency, when your boiler was commissioned a tool that is required to properly do so is commonly known as a "combustion analyzer".  It is an expensive specialized piece of equipment but one that a Certified Baxi Technician will likely own.  When your boiler was commissioned, two print outs should have been left behind.  A maximum input or "high fire" report and a minimum "low fire" report.  Part of the standard information included in the analysis is combustion efficiency at the respective firing rates.

 

System efficiency - There are some modifications that can be made through the Siemens QAA73 controller to maximize efficiency and essentially "custom fit" the boiler to your home or system.  The outdoor sensor plays a significant role in gaining system efficiency.  If I understand your post correctly, it sounds like you are running high temperature baseboard and lower temperature radiant heat.  In order to gain more efficiency, you should consider eliminating the "high temp" baseboard and installing a higher output baseboard.  We have had tremendous success with the "Heating Edge" product ( see: http://www.smithsenvironmental.com/html/he_conv.html ).  We can help your installer calculate the amount required for your "high temp" zone.  This will allow you to operate your entire house on one, lower water temperature or "system design temp".  By having one lower water temperature it would then likely make sense for you to look at installing the weather sensor which would enable the on-board "heat curve" software.  For every 3 degrees you lower your system design temperature you will gain 1% system efficiency.  Additionally, when the hydronic return water to the boiler is 140 deg. F or cooler you will also drive your combustion efficiency up by condensing the water vapor (combustion bi product) into liquid and putting the thermal energy from it into your home rather than the backyard.  You get to "double dip" on this one!

 

The Baxi HT's when properly commissioned and maintained are an amazing piece of equipment.  That said, they are a little bit more technical than some more simple units out there. 

 Always ask your installer / service contractor if they are BAXI CERTIFIED.  All Baxi certified contractors have undergone not only training but have invested time and money in advanced training tools, equipment, and have been tested and approved.  They are able to offer twice the standard parts warranty and are empowered to sell the extended 10 year parts and labor warranty.They will have a laminated wallet card and a Baxi Certification number.  

Hope this helps!  Let me know if there is anything I can do! 

 

-Tom

Joe_

Tom

Your knowledge seems very in depth. Since the last post the installer has been back. The temperature fluctuations with DHW have gone away however the DHW still seems to get to hot. The only correlation I could see was the installer turned the knob down for heating temp thus lowering how hot the radiators got. I did not agree so I turned the heat knob almost to full but now deal with very hot water. I'm very happy with the system and it seems to using little propane. Should I push for a rep to come and look at the system? I don't think the installer will helpful any longer. I was quoted around 150 I believe to have the outdoor sensor installed, sound fair and worth it? The installer did not seem to interested in doing so as I think he was not aware of the overall cost savings/ efficiency.



-Joe

TFL

Baxi HT 380

Joe,

I'm not clear on which water is too hot. Is the domestic hot water (DHW) too hot or is the central heat (CH) water too hot?

I am sorry to hear that your tech will not come back.  I would appreciate any specifics you could share with me with regard to this installer (email only please) as this is not appropriate representation / support of Baxi products.

If it is domestic that is too hot, is it consistently too hot or are there fluxuations with moments of "too hot"? If it is the latter, please see my previous reply under the "DHW" section.  Please clarify this for me.

The setpoints / knobs for DHW and CH are mutually exclusive.  One has absolutely no effect on the other.  He turned down the CH knob (on the left with the radiator icon) to correct / adjust the DHW temp?

Yes, that sounds like a fair price for the outdoor reset provided it is properly set up and you are given a tutorial on how to tweak it and what human behavioral changes may be required. Your installer is mostly correct based on what you have given for system information.  I would say you are "putting the cart before the horse" doing this now (see "system efficiency" in my previous post).  We should focus on getting your houses design temp to one, lower temp first.  Then you can really pull the cash register lever "CHA CHING" and put the reset on.  If you want to give it a shot now, go for it.

Please clarify above for me and I'll try to steer you from there.

Thanks,

Tom

Joe_

Baxi HT 380

Hi Tom,



Yes the DHW is too hot. I just took the kitchen faucet temp and it read 144 degrees f, than dropped down to 118 and reached 123 and held steady for at least 1 minute. I just don't think the installer knows a lot about the system although more than myself. The DHW does fluctuate. So the set point knobs, for winter heat settings should be turned all the way up correct? For Heat?

NRT_Rob

all DHW systems

should have a hardware tempering valve in them in case of higher temp fluctuations in the line, after the heat source.



that would resolve "high temp" fluctuations, and protect you and your family from any malfunction as well.

TFL

Baxi HT380

Hi Joe,

It is possible to get a DHW spike at first if the boiler has been in a heat call recently and the boiler is not piped primary / secondary.  The reason for this is that the software includes a "post purge" or "pump over run time" after flame-out.  The spirit of this is to move the heat out of the heat exchanger / boiler and into the living space where you will benefit from the energy.



If the boiler is piped in/out through zone valves, when the zone is satisfied and the zone valve closes, the Baxi will post purge or "bypass" through the flat plate heat exchanger in order to protect the primary heat exchanger by moving the latent heat / water out of it.



I'll go on the record as saying that all low-mass, wall hung, condensing gas boilers should be piped primary / secondary.  Baxi however, is the only combi with an internal bypass to protect the pump and heat exchanger in the event of a "dead head".



Send me an email through this site and I'll put you in touch with some Baxi Certified techs that come over and identify and remedy your concerns / issues.  Should be fairly straight forward once they are in front of it.



Thanks,

Tom

Joe_

Tom

Did you get my message? I had sent a week or so ago?



Thanks,

Joe

DWPlbg

Baxi Madness

Thank you all for the posts. I did an HT 380 install with an On-Site Tech Rep from a Distributor. It involved a Laptop, and those crazy alien gauges that got stuffed everywhere.

It has worked well for a while, but may need revisiting.

May need to find locally-stocked parts soon.



Current Issue :

Flow Indicator LED (faucet shape) does not light on DHW flow condition. Switch to CH Mode (Snowflake Icon) on Boiler and Coil LED as well as Burner LED light up, Burner goes to Low Fire, Blower ramps up, Burner hits High Fire. Burner poops out, Blower mocks you for another 30 seconds or so. Repeat. That's great for the CH, but still no temp on DHW.



"Reset"

Switch to Summer Mode (Sun Icon), run Faucet, no LED, no Fire. Leave Faucet running, switch back and forth from "0" to Summer. Flow LED lights, Burner goes to Low Fire, Flow LED flashes right before High Fire, which last just a few seconds.



Checked Concentric Vent 90, and Side Wall Vent Kit, both clear, and graded away from Boiler. Cleaned Ignitor & Sensor. DId not clean Main Burner. Cold Water Inlet Screen is clean.



Any suggestions, please?



-Dave



I was thinking Flow Sensor, but failed to contact a Technician.

Lyrad

Baxi Luna help

I would appreciate anyone's help out there with a problem with our Baxi Luna HT 380.  We have had our Baxi for about 6 years now and I love it.  However,  we have problems with our unit every time we get propane delivered.  An error code of  E1 33 comes up (gas supply fault) on every fill.  We are running a 500 gal. propane tank and we are on keep fill, and live in northern Minnesota.  The tank never drops below 20 % but if we go on vacation and we get a fill, the boiler will not work unless someone can turn the reset switch.  This is very frustrating and I can hardly find anyone around here to answer this question.  Is it that touchy of a system that a propane fill will throw it off? Do we have the wrong size regulators on?  Thanks for any help out there!!

Tom_133

My guess

The delivery driver is shutting off the tank while he fills. If this happens when the boiler is running it will lock out on attempts to fire.



Thats just a guess though. Sounds dumb but also make sure you have a good ground on the electrical supply, that can give random lockouts.

befudled1

elementary information

i am new to baxi heating-had one installed about a year ago. familiar with either setting for domestic hot water or central heating. am concerned that during the summner months it (temperature) in my house will be hot- can i adjust the central heating temperature so that my hot water pipes are not so hot? is there any way of getting a qualified, insured technician to come and give me some elementary instructions.  dean

Tom_133

Baxi

Dean,



The process of making DHW is separate from making CH or heating, especially on a Baxi. My thinking is you have a different problem perhaps something is calling for heat when it shouldn't be. The easy fix is to set the switch on the front of the unit to the sun symbol, it's probably on the snowflake currently. This is considered the summer setting, which turns off all space heating. Just don't forget to swap it back this fall.