HTP UFT Tankless boiler

doctorman

NY_Rob said:

^ looks like you're in spec... so I guess it's good!

It certainly wouldn't hurt to check it once in a while... it will at least let you know something's going on if you see a change in the numbers.

HTP should have implemented an economy and Power mode and let the user switch.
It would be smart for the boiler to sense what the demand is and power to it and then go to economy mode and maintain it.
Do the HTP boilders get a Firmware update? can we update them somehow?

NY_Rob

^ yeah... you want new firmware? Buy a new control board and display board and hope it's not new old stock. $350+ should cover it.

... I'm not kidding, been down that road with HTP!

doctorman

Manual Page 54
We can adjust the curve and raise the temp based on the Outside sensor
function 4:OH and 7:CL

and Function 5:OL and 6:cH

Also I would change the 8:0F from 68 to 74F since the house is slab on grade and inside could be colder than outside.


Changed my 8:0F to 74F

and my 7:CL to 105F from 86F

there is not much point to change the rest,

Leon82

You should let it run and see how it heats before you change stuff.

With some fuel bills you can use some math to find out a somewhat close curve

doctorman

there is a boost option option 9:bt that will run 15F more than the ODR...
at option 7:cl set to 105 , it was still cold , so increased it to 122.

I guess you are 100% right , I need the switch, despite all these fancy curve option, nothing is like 180F water to bring up the temp in the house quickly and then we let the boiler maintain it with the ODR.

Ironman

Why do you need to "bring up the temperature of the house"? As I explained earlier, you don't want to setback the thermostat of a mod/con boiler. Leave it at one temp and let the ODR do its thing. You're defeating the purpose of a modulating condensing boiler by using setback and then trying to override the ODR curve. You're actually making the boiler a lot less efficient and the house less comfortable by using setback.

doctorman

Ironman said:

Why do you need to "bring up the temperature of the house"? As I explained earlier, you don't want to setback the thermostat of a mod/con boiler. Leave it at one temp and let the ODR do its thing. You're defeating the purpose of a modulating condensing boiler by using setback and then trying to override the ODR curve. You're actually making the boiler a lot less efficient and the house less comfortable by using setback.

I understand but it took the house almost one day to reach 65F from 60F, which is most probably due to bad baseboard (too little) or covered baseboard with boxes and furniture.
So either I have to raise the temp or add more baseboard to heat up the house.

playing with different setting till I get a feel which I will go

ideally, I will add the switch to the ODR and bring up the temp to 72F with 180F water and then switch it off and let the boiler maintain it at that temp with high efficiency and original settings.

If not I have to add more baseboard or radiator.

Ironman

The boost feature, properly set, would do what your asking. It makes no sense to me to try and accomplish it by putting a manual switch in the sensor wire.

Most (if not all), German mod/cons do not have a boost feature because they understand it's a fuel waster. HTP is an American company that understands Amaericans are still stuck in the last century in their thinking about energy savings and they still wanna do setback. Therefore, the boiler has a boost feature which can be set to incrementally increase the SWT to compensate for our stubborn, backward thinking about energy savings.

Ironman

Let add a further note:
When the ODR curve is CORRECTLY set to match the actual heat loss of the structure, the thermostat will actually become unnecessary.

A lot of folks have a hard time accepting that, but I've got jobs where that's all that's controlling the boiler - just the ODR, no stat. That includes one right next door which has been running that way for over 5 years and the temp stays at 68* all heating season.

SeymourCates

@Ironman

Although an excellent concept in theory, the capability of maintaining a set temperature without the use of the 'stat is simply not present. The problem is the variability of the infiltration. Since the average house suffers from an infiltration heatloss that is typically 40% of the total heatloss, the BTU requirements go up significantly when the wind starts howling. It is not inconceivable to require another 6-7 degrees of SWT to maintain the building when the wind picks up severely. The only way around this, other than indoor reset, is to lift the curve and allow the stats to operate traditionally at times so the outlying day with heavy wind is covered.

Ironman

@SeymourCates,

Maybe you should read my post again. It's not theory, I've got jobs ACTUALLY doing it! That's not just coming from me, my customers have testified to it.

Viessman does it that way with most of their mod/cons. So does Buderus with their Logamatic control.

hot_rod

SeymourCates said:

@Ironman

Although an excellent concept in theory, the capability of maintaining a set temperature without the use of the 'stat is simply not present. The problem is the variability of the infiltration. Since the average house suffers from an infiltration heatloss that is typically 40% of the total heatloss, the BTU requirements go up significantly when the wind starts howling. It is not inconceivable to require another 6-7 degrees of SWT to maintain the building when the wind picks up severely. The only way around this, other than indoor reset, is to lift the curve and allow the stats to operate traditionally at times so the outlying day with heavy wind is covered.

tekmar had this right many years ago, they promoted ODR with indoor feedback.

Especially useful for quick and high occupancy changes like public buildings or churches. While one benefit is controlling over-shoot, your point about the load increasing without the outdoor temperature changing is valid.

Inside our buildings we refer to this as a draft, outside we call it chill factor.

SeymourCates

@hot rod

Yes, Tekmar certainly has it correct when they combine OAR with indoor feedback. When the load increases above the heating curve, as it certainly must due to the wind chill factor, the boiler can respond to the falling 'stat temperature by increasing the SWT slightly. This is a complicated algorithm however, as the mass of the air in the building requires a very slow response by the control. I have not had the pleasure of utilizing it but would certainly like to do so in the future.

Here in Canada, the winds can thoroughly trash the best of the OAR heating curves. Those that have no wind to contend with should be forever grateful.

Maybe Viessman and Buderas could stand to learn something from Tekmar.

doctorman

1) after a week the unit is working great,
my smallest zone is refusing to heat and I am sure it is the amount of baseboard and lack of insulation
a 300sqft room slab on grade , 50% windows and no insulation at the bottom, needs 20KBTU to heat up...

I think it only has 11feet of baseboard under the covers, so I need to add another 15feet or so.

any recommendation on the baseboad type/ radiator /some sort of heat exchange?


2) HTP Boiler is leaking from condensation port
contacted HTP and they said I need a new
Condensate Trap Assembly- 7855P-053

it is sad that they can not send it directly to me instead referring me to my supplyhouse to get that, and HTP does not provide labor or instructions for this part replacement.

any guide on how to replace this? can I do it myself or is it involved?

NY_Rob

When I needed a part replaced under warranty, I called the supply house where I purchased the boiler, explained the situation and HTP's recommendation to replace the part.
The supply house got the part from HTP, I installed it and gave the defective part back to the supply house. The supply house filed the warranty claim and handled the return.