We have a radiant heat system we believe was not installed correctly or according to specifications we were provided. We were told we would have a system with a 90% condensing boiler for radiant. Instead, we have a gas water heater (Lochinvar Model number LVL 041G0). From what I understand, a gas water heater and a boiler are not the same things? The second issue is that the tubes run from the water heater to the floor with just insulation below and floor above in the basement. There do not appear to be any type of metal transfer plates to force the heat to be conducted to the floor. This, from what I understand, is incorrect. Is this ever an acceptable way to install radiant heat? We have a large basement and the pipes run a very long way to get to the master bath. The result of the problems seems to be that our system is extremely inefficient/ non-functional. The radiant system is in the sunroom (right over the tank) and the master bath (opposite end of the house). The water heater runs for around 12 hours a day or more, and costs a fortune to run. Even after running for hours and hours for weeks, the floor in the bathroom is still freezing and the thermostat in the bathroom attached to the radiant heat still reads 57 degrees even when we have it set for 64. Final issue is that our installer indicated that the thermostat attached to the radiant heat reads the room temperature and not the floor temperature. The thermostat is called Watts Radiant. Is this actually true? We don't understand why this would ever be this way instead of having a thermostat that reads the floor temperature.

Of what value would reading the floor temperature be? If the thermostats are calling for heat as it is and the system can't satisfy the room needs, reading the floor temperature won't do anything for you.

If it can't reach the 64 degrees that you want it to, then there is definitely a problem. I'd have someone come in to fix it.

The water heater runs for around 12 hours a day or more, and costs a fortune to run.

Okay, but wasn't the system really inexpensive up front?

What is the temperature of the water leaving the heater and the temperature of the water returning, and what is the flow rate in gpm?

No it was not really inexpensive up front. We were told we were getting a boiler system, which was more costly. We paid $13,000 (above and beyond the regular costs of installing a geothermal system) in order to get radiant heat in three rooms (kitchen, sunroom and master bath).

The thermostat temp on the hot water heater reads 100 and 140 on the needle. Not sure what the flow rate is, how do we find that out?

$13,000? And for that you got a gas hot water heater, a circulation pump and some pex tubing? Is there some kind of flow indicator on the circulation pump? What is the make and model?

Aren't there any temperature indicators on the leaving and return lines?

You have a power vented water heater. Energy factor by manufacture of .67 energy star rated for a water heater.
You do not have a boiler, let alone condensing type above 90%
Heat transfer plates are a necessary best used item for most parts of the country and best used to get any staple up system working at its optimum. Location is usually the key here combined with the building insulation.
A budget system may chose not to have plates but if you are in a cold climate you will need them.
Typically without heat plates you will need delivered water temperature above 135 and closer to 145 to get the system to work.
Might also look at loop length, pipe spacing, on average you will want not more than a 300 foot run of 1/2 pex, 8" on center (up/back each joist bay with a 16" joist pattern).
Zoning (number of thermostats)? How big is the house? Location?
Last question is your domestic hot water coming of this appliance as well?
Dan

You could take a kitchen or IR thermometer and measure the temperature of the tubes going to and from the master bath. That helps with diagnostics.

Sounds like another HVAC "pro" horror story...twice the cost of a good system for a bad design/installation. I assume you contacted the HVAC designer/installer and didn't receive much in the way of kindly assistance. If the HVAC designer/installer is from your state, you might be able to contact your state attorney general to seek remedy or just seek a normal legal remedy. If the HVAC designer/installer is from out-of-state, you are pretty much on your own.

If the floor temp is not above the desired indoor room temp, the floor is not going to provide any heat gain to the room. So that is one reason for measuring floor temp when initially troubleshooting a system. The floor temp, outdoor temp and indoor temp should all be used by controller to maintain a comfortable indoor temp. However, the system first has to be properly designed and installed so to generate the required upward heat flux and associated required room heat gain that aligns with the room heat loss. Without knowing the design details of what was installed, it will be difficult to sort this out. Below-floor systems are either very expensive when done right (using expensive plates) or horribly inefficient and expensive to operate otherwise. Either way, one is usually better served by using mini-splits or even electric baseboard in lieu of below-floor hydronic radiant.

No temperature indicators on the lines.

Dan:
We are in PA (cold climate). 5,000 square foot house, two zone heating & cooling system. This should not have been a budget system. Just the radiant was $13,000, we also paid for geothermal and propane backup, the whole thing was more than $60,000 for HVAC. This is a high-end builder and the house was $1mil+ Our domestic hot water is not coming off of the appliance, we have two other hot water heaters plus a third that heats water off the geothermal...

Borst:
We are just starting to bring the issues up w/ our builder, I do not know yet whether he will make this right or not but I hope so. Both the builder and the installer are from our state.

I can take a picture, if it is possible for me to post one on here and if that would be helpful? I am just trying to be armed with the info I need because we got a lot of excuses from the installer on why this hasn't worked.

Ok,
You have a 5,000 square foot house,
The model water heater you called out has a BTU rating of 40,000 btu - efficiency assume 80 % 32,000 BTU to heat a 5,000 sq ft house, a disservice. Part one of the problem, reality is you will need about 125,000 btus may not need it all but that is about right in there. A condensing boiler in that range will deliver 95% 125,000 btu or 118,750 BTU delivered. This would provide about 23.5 BTU square foot, about right for a cold day. Check the gas piping now to see if it can support the 125,000 BTU load, this would be in question as well.
Next you need to have an understanding of how they ran the pex pipe, request a loop lay out, that will help. Did they staple up to the floor, or suspend in some way in the joist system?
Heat plates are a needed item in your climate, they do not need to be the high end top dollar extruded type, but you will want a plate system of some sort to extract the heat and pass it to the floor.
8" pipe pattern 3/4 sub floor 3/4 finished floor max, heat plates. That is what I would be looking for to start.
Carpeted rooms will make a hit on performance.
Pictures are good.
Dan

Given that you are still working with the builder and all parties are in-state, you should be able to make this right. We are not big fans of under-floor hydronic radiant systems because of ROI and efficiency concerns, however, if $$$ are not a limitation, this is certainly a comfortable heating system. We would agree with Dan that using heat plates and avoiding carpets or anything that increases the R-value above the heated floor surface should be avoided if you care at all about heating system efficiency and operational $$$...which you should to some extent given that this is green building site forum after all.

You have geothermal and (additional) propane backup? Why was this hot water heater system under discussion separated from all that? Is the home all new construction or some retrofit?

I will try to take some pictures today.
We have ceramic tile over the radiant in the bathroom and hardwood over the radiant in the sunroom. We specifically wanted this system to be as energy efficient as possible, that's why we did geothermal and why we were (supposed to) have a boiler for radiant heat instead of electric, etc.

ICFHybrid:
We have geothermal, an additional propane backup and then we were to have a radiant heat system for those three rooms for floor warming. The house was new construction. We essentially put in three separate heating systems. Not sure if that was the best way but that was what we were told we needed to have the energy-saving benefits of geothermal and to have the floor warming as well...

Please clarify,
how many square feet is the in floor heat area?
All of the house or a small portion?
Dan

Energy efficiency comes from managing solar gain, proper insulation and sealing against infiltration.

What's left over is handled with appropriate energy source selection and implementation. Sorry to say that what you have, with three systems, is builder revenue enhancement and profit efficiency.

ETA: Floor warming in a sunroom?  That must be for the few days you have NO insolation, obviously making that a 4 season sunroom, right?

Posted By Blueridgecompany.com on 01 Dec 2013 11:46 AM
You have a power vented water heater. Energy factor by manufacture of .67 energy star rated for a water heater.

The EF test number is a completely irrelevant in a space heating application where the burner is running a very high duty cycle. EF tests are assuming it's only heating ~64 gallons/day, with a preponderance of idling time during which heat is being convected out of the center flue heat exchanger.  That is a very different duty-cycle than any space heating app, and even mentioning EF takes it down a strange path.  Most power-vented non-condensing water heaters hit about 80% steady-state combustion efficiency, and at the duty cycle this one is running it's surely averaging close to it's steady-state numbers.

A 5000' code-min new home in a central PA climate should come in well under 70,000BTU/hr for a design-day heat load, but will probably still be well over the ~32,000 BTU/hr output of the hot water heater. 

But the burner is just the half of it- getting sufficient heat out of the tubing and into the floor at hot-water-heater temps will almost always take some metal heat transfer plates.  If they went with EPDM tubing (Onix) you might get there, depending on all of the particulars of the floor stackup, but EPDM tubing has other issues of concern.

You can turn the temperature up on the water heater to get more heat delivered to the master bath.