New Boiler, Indirect Hot Water Heater
Hi Stan,
I wanted to summarize our experience with a new boiler and indirect hot water heater for our Rummer. Please feel free to edit and distribute any way you see fit for your Rummer web site.
JB
Our Old Boiler and Hot Water Heater
Our Ultra High Efficiency (80%) Weil-McClain boiler was approximately 24 years old and showed signs of a rusting heat exchanger. Our hot water heater was about 11 years old but functioning. We sought to take advantage of the state and federal tax credits ending in 2010 to replace both the boiler and hot water heater.
New Condensing Boiler Technology
Condensing boiler technology has changed dramatically in 24 years. The idea behind condensing boilers is that they heat water to fairly low temperature and circulate this “warm water” through the radiant slab in the home. Operating temperature of the heated water is only ~90 degrees Fahrenheit and at 96% or greater boiler efficiency, most all of the heat from combustion is transferred to the water. Consequently, the exhaust gas from the boiler is only at about room temperature, or fairly “cool”, which causes water to condense in the exhaust tube which is continuous with the outside, cooler air. The boiler has a condensate trap that ultimately collects and vents the water outside the home through a drip tube. Old condensing boilers operated at lower efficiency and higher temperatures, heating the metal exhaust tube so that condensation was reduced to a minimum. The modern condensing boiler uses a PVC or “plastic” combination intake/exhaust stack since exhaust gas is so “cool.”
Indirect Hot Water Heater
We were most impressed with the Knight/Lochinvar and Weil-McClain boilers based on technical information obtained from manufacturer’s web sites and interviews with radiant heating specialists in Portland. We had a unique opportunity to adopt indirect hot water heater technology since we wanted to replace our aged hot water heater as well. Indirect hot water heaters are clever beasts. A hot water circuit that is part of the radiant slab circuit and controlled by the boiler feeds a stainless steel loop that spirals within the hot water “tank”. A fairly low volume of potable water is present in a separate stainless steel loop in the tank, so heat transfers from the hot boiler water loop to the cold potable water loop. When there is a call for domestic hot water, i.e., a shower, the boiler shuts off the radiant slab circulation pump and energizes the pump for the hot water circuit, and at the same time, heats the boiler water to 120 degrees Fahrenheit. Less than 10 gallons of water are at set temperature at any given time, but the heat transfer is so efficient that fresh cold water reaches set temperature before the residual hot water in the tank is exhausted: you have a continuous supply of hot water. So there is no separate, gas-burning heater as in conventional hot water heaters. The condensing boiler heats water for the radiant slab and for the hot water. In the summertime, the radiant slab circuit is shut down so only the hot water heater circuit operates.
The Bottom Line
We obtained two formal quotes from the Heating Specialist and from All Temp. The Heating Specialist installs different models of boilers but prefers the Weil McClain boiler, and All Temp installs Knight/Lochinvar boilers. We decided to go with the Heating Specialist based on the price quote, which was about 6% less, and that they would install the Weill McClain boiler and indirect hot water heater.
Our Installation Experience
Our installer removed our old system and installed our new system over 3 days in October. The staff was courteous and professional. There were some issues post-installation. The condensate drain port leaked at the base of the boiler and had to be tightened. The PVC exhaust stack leaked and needed to be replaced. These could be considered minor issues in the fit and finish class. However, the indirect hot water heater leak was not by any means a minor issue. There is an accessory port on the hot water heater that should be terminated with a proper cap. The plastic cap on our unit heated up, cracked, and sprayed hot water in our garage. The steam set off the fire alarm, so this was a considerable leak. While the boiler has numerous safety features, there isn’t one configured to cope with an open accessory port (I am discussing this with Weill McClain to see if there is something that can be done). The Heating Specialist came within 10 minutes, and terminated the hot water heater. The indirect hot water heater is a newer technology and requires specialized experience for installation. I let the Heating Specialist know that we were completely dissatisfied with the error on the hot water heater installation and requested that they pay the $90 charge from Brinks Home Security to test our alarm system control box that was doused with water. They did so, immediately. While the leak should not have happened, the response was immediate and to our satisfaction.
Performance
Our home is comfortable in a way that we didn’t experience with our old boiler. The uniformity of the heating is better, and this probably relates to the extensive air bleeding done during installation of the new boiler. The new unit is extremely quiet and offers us information on its performance through a digital interface. Our 12 year old daughter has yet to challenge the hot water heater during her “extensive” showers. We are totally satisfied with the Weil-McClain boiler, and have recommended both the Heating Specialist and Weil-McClain to a friend. We told her about the installation error on the hot water heater, which I’m certain will not happen again. We do not yet have enough information to describe gas savings with our new system, but we’ll update you next year after a full heating season.
Decisions
We decided to invest in the new ultra high efficiency boiler and indirect hot water heater because we plan to live in our Rummer for many, many years. The system we installed was expensive and if you are selling your home in 3-5 years, would not make sense for you. The tax credits/rebates helped soften the financial issues for us. I would not have replaced the hot water heater and boiler at the same time if the hot water heater were newer, but in our case, we needed both at the same time. There are solutions to heating a Rummer that are far less than the system I describe here, it simply depends on your long term life plan.
I wanted to summarize our experience with a new boiler and indirect hot water heater for our Rummer. Please feel free to edit and distribute any way you see fit for your Rummer web site.
JB
Our Old Boiler and Hot Water Heater
Our Ultra High Efficiency (80%) Weil-McClain boiler was approximately 24 years old and showed signs of a rusting heat exchanger. Our hot water heater was about 11 years old but functioning. We sought to take advantage of the state and federal tax credits ending in 2010 to replace both the boiler and hot water heater.
New Condensing Boiler Technology
Condensing boiler technology has changed dramatically in 24 years. The idea behind condensing boilers is that they heat water to fairly low temperature and circulate this “warm water” through the radiant slab in the home. Operating temperature of the heated water is only ~90 degrees Fahrenheit and at 96% or greater boiler efficiency, most all of the heat from combustion is transferred to the water. Consequently, the exhaust gas from the boiler is only at about room temperature, or fairly “cool”, which causes water to condense in the exhaust tube which is continuous with the outside, cooler air. The boiler has a condensate trap that ultimately collects and vents the water outside the home through a drip tube. Old condensing boilers operated at lower efficiency and higher temperatures, heating the metal exhaust tube so that condensation was reduced to a minimum. The modern condensing boiler uses a PVC or “plastic” combination intake/exhaust stack since exhaust gas is so “cool.”
Indirect Hot Water Heater
We were most impressed with the Knight/Lochinvar and Weil-McClain boilers based on technical information obtained from manufacturer’s web sites and interviews with radiant heating specialists in Portland. We had a unique opportunity to adopt indirect hot water heater technology since we wanted to replace our aged hot water heater as well. Indirect hot water heaters are clever beasts. A hot water circuit that is part of the radiant slab circuit and controlled by the boiler feeds a stainless steel loop that spirals within the hot water “tank”. A fairly low volume of potable water is present in a separate stainless steel loop in the tank, so heat transfers from the hot boiler water loop to the cold potable water loop. When there is a call for domestic hot water, i.e., a shower, the boiler shuts off the radiant slab circulation pump and energizes the pump for the hot water circuit, and at the same time, heats the boiler water to 120 degrees Fahrenheit. Less than 10 gallons of water are at set temperature at any given time, but the heat transfer is so efficient that fresh cold water reaches set temperature before the residual hot water in the tank is exhausted: you have a continuous supply of hot water. So there is no separate, gas-burning heater as in conventional hot water heaters. The condensing boiler heats water for the radiant slab and for the hot water. In the summertime, the radiant slab circuit is shut down so only the hot water heater circuit operates.
The Bottom Line
We obtained two formal quotes from the Heating Specialist and from All Temp. The Heating Specialist installs different models of boilers but prefers the Weil McClain boiler, and All Temp installs Knight/Lochinvar boilers. We decided to go with the Heating Specialist based on the price quote, which was about 6% less, and that they would install the Weill McClain boiler and indirect hot water heater.
Our Installation Experience
Our installer removed our old system and installed our new system over 3 days in October. The staff was courteous and professional. There were some issues post-installation. The condensate drain port leaked at the base of the boiler and had to be tightened. The PVC exhaust stack leaked and needed to be replaced. These could be considered minor issues in the fit and finish class. However, the indirect hot water heater leak was not by any means a minor issue. There is an accessory port on the hot water heater that should be terminated with a proper cap. The plastic cap on our unit heated up, cracked, and sprayed hot water in our garage. The steam set off the fire alarm, so this was a considerable leak. While the boiler has numerous safety features, there isn’t one configured to cope with an open accessory port (I am discussing this with Weill McClain to see if there is something that can be done). The Heating Specialist came within 10 minutes, and terminated the hot water heater. The indirect hot water heater is a newer technology and requires specialized experience for installation. I let the Heating Specialist know that we were completely dissatisfied with the error on the hot water heater installation and requested that they pay the $90 charge from Brinks Home Security to test our alarm system control box that was doused with water. They did so, immediately. While the leak should not have happened, the response was immediate and to our satisfaction.
Performance
Our home is comfortable in a way that we didn’t experience with our old boiler. The uniformity of the heating is better, and this probably relates to the extensive air bleeding done during installation of the new boiler. The new unit is extremely quiet and offers us information on its performance through a digital interface. Our 12 year old daughter has yet to challenge the hot water heater during her “extensive” showers. We are totally satisfied with the Weil-McClain boiler, and have recommended both the Heating Specialist and Weil-McClain to a friend. We told her about the installation error on the hot water heater, which I’m certain will not happen again. We do not yet have enough information to describe gas savings with our new system, but we’ll update you next year after a full heating season.
Decisions
We decided to invest in the new ultra high efficiency boiler and indirect hot water heater because we plan to live in our Rummer for many, many years. The system we installed was expensive and if you are selling your home in 3-5 years, would not make sense for you. The tax credits/rebates helped soften the financial issues for us. I would not have replaced the hot water heater and boiler at the same time if the hot water heater were newer, but in our case, we needed both at the same time. There are solutions to heating a Rummer that are far less than the system I describe here, it simply depends on your long term life plan.