So, our house is turning 28 this year. (Actually, only about half of it, as it got extended by my parents, but the old part was completly redone as well.) Since day 1, a Buderus 32kW oil fueled central heating system together with a matching 300l hot water storage worked pretty well in our basement next to the laundry room with hardly any problems for the first 15 years.
Then, the first problems started to occur. The main electro-mechanical control failed and had been replaced. A few months later, the storage tank was clogged with mineral deposit. We had the choice between a new storage tank and a few days of hard work to clean the old one out. As we were tight on money, my father opend it up and found a 20cm thick layer of deposits arround the inside of the tank, which he knocked out by hand. He had to repeat that procedure 5 years later again. In 2012, the electronics went again and we had them replaced with a different, used one, as my parents were planning to get a new system in the soon future anyway. Than, in 2013, while we were on vacation, my grandma recognized that she wouldn't get any more hot water. It would only be sllightly warm. The technican had to replace a circulation pump, clean out the heat exchanger in the tank, replace several valves and a (pretty pricey) expansion tank. Now, mid last year, the burner blower fan repeatedly refused to start up. It was repaired twice, as a new one that would fit (the system was considered high-tech in the 80s, but is completly overengeneered by todays standards) would have to be installed together with a complete new burner assembly which summed up to over 2000€ only in parts, with several hundreds in labor and new safety certifaction, which would have been about 200€ on top on top. So, as it kept going again a few months each time and the repairs weren't to expensive, we knew we had to act, but not in an instant.
After several informations, comparisons, checks and doublechecks, the best option was the Rotex oil fueled condesing heating system with matching water tank. We had to get a high temperature system due to the size and heating layout of our home (so no heatpumps possible). We thought about switching to wood pellets, but either we had to add the pellets manually, or we would had to spend even more for a remodel of our oil storage room, and the system was twice as expensive as what we got now anyway. So we were stuck with oil. Rotex was the best choice as our technician of choice serviceses a lot (not only his own) systems, so he knew a thing or two about them and had a lot parts in storage. Further, the hot water storage tanks are complete flow-through systems. This means the tank it self only contains about 300l of water that stay in that tank for pretty much the better part of 10 years or until it needs service. All warm water is then heated by flowing through a big, stainless steal heat exchanger loop in the tank. Because the pipe diameters is quite small, the system is clogg-proof. We have pretty hard water (42°dh or about 43 grains per gallon), so this system allows for pretty limescale proof operation without costly maintenance. We had the option to add solar water heating, but there is really only space for 1 well oriented collector on our roof and, with runnig costs of insurence and maintanance, it didn't math out to well.
To all of you who don't know full condesation systems: Basicly, the exhaust gases of the burner are cooled to a point where the water vapor in them condenses. That cooling is done by the cold side of heating circut.
Our old system was oversized by todays standard (32kW), so we went along with adjustable 20kW system. The burner output can be set between 18 and 23kW. The system uses a one piece burner housing and condeser unit unlike others.
We ordered the system in September last year, but were told that it won't be installed until this spring. My mum of instantly looked at the man and said: „You know what will happen? On Christmas we'll sit here without any heating!" "If that happens, I will take care of that situation! Take my word!" he said.
25.12.2014: My mum stands beside the technician in our basement, shows him the not runnig system and says: "So, go ahead and take care of it!" He got to start it again, but 2 days later, it finaly gave up. He managed to construct a system that consisted of 3 bricks, several pieces of wire and some sheet metal to attach a different burner assembly. One just had to touch it a bit careless and that room would probably have gone up in flames. Though, he did not bill us anything for anything. That's what I call customer service.
So, they called last week and said they'd start installation today. They came a bit late, but were done with todays work by 4pm. Today, they took out the old unit (pictures below) and prepared everything for the next day.
Tomorrow, they will first do a re-regulation of the flow rates. That basicly means they limit the flow of any heating heating circut in this household so that the backflow to the condesation unit can be assured to stay beneath a certain temperature limit (I think about 60°C, 140°F) to ensure proper condesation. Then, the venting will be redone. As the exhaust gases are cooled below 100°C in any case, our jimney is fitted with a big, double walled plastic pipe. The inner pipe is designed to allow perfect airflow while the outer part is used as air intake. Then, they'll put in tank and heating unit and hook them up. On wednesday, they will fill the system up, configure it and check it. So I hope I can shower again on wednesday evening.
I'll keep you posted. If you got any questions, I'll try to answer them.
Best wishes to all of you
Henrik
Then, the first problems started to occur. The main electro-mechanical control failed and had been replaced. A few months later, the storage tank was clogged with mineral deposit. We had the choice between a new storage tank and a few days of hard work to clean the old one out. As we were tight on money, my father opend it up and found a 20cm thick layer of deposits arround the inside of the tank, which he knocked out by hand. He had to repeat that procedure 5 years later again. In 2012, the electronics went again and we had them replaced with a different, used one, as my parents were planning to get a new system in the soon future anyway. Than, in 2013, while we were on vacation, my grandma recognized that she wouldn't get any more hot water. It would only be sllightly warm. The technican had to replace a circulation pump, clean out the heat exchanger in the tank, replace several valves and a (pretty pricey) expansion tank. Now, mid last year, the burner blower fan repeatedly refused to start up. It was repaired twice, as a new one that would fit (the system was considered high-tech in the 80s, but is completly overengeneered by todays standards) would have to be installed together with a complete new burner assembly which summed up to over 2000€ only in parts, with several hundreds in labor and new safety certifaction, which would have been about 200€ on top on top. So, as it kept going again a few months each time and the repairs weren't to expensive, we knew we had to act, but not in an instant.
After several informations, comparisons, checks and doublechecks, the best option was the Rotex oil fueled condesing heating system with matching water tank. We had to get a high temperature system due to the size and heating layout of our home (so no heatpumps possible). We thought about switching to wood pellets, but either we had to add the pellets manually, or we would had to spend even more for a remodel of our oil storage room, and the system was twice as expensive as what we got now anyway. So we were stuck with oil. Rotex was the best choice as our technician of choice serviceses a lot (not only his own) systems, so he knew a thing or two about them and had a lot parts in storage. Further, the hot water storage tanks are complete flow-through systems. This means the tank it self only contains about 300l of water that stay in that tank for pretty much the better part of 10 years or until it needs service. All warm water is then heated by flowing through a big, stainless steal heat exchanger loop in the tank. Because the pipe diameters is quite small, the system is clogg-proof. We have pretty hard water (42°dh or about 43 grains per gallon), so this system allows for pretty limescale proof operation without costly maintenance. We had the option to add solar water heating, but there is really only space for 1 well oriented collector on our roof and, with runnig costs of insurence and maintanance, it didn't math out to well.
To all of you who don't know full condesation systems: Basicly, the exhaust gases of the burner are cooled to a point where the water vapor in them condenses. That cooling is done by the cold side of heating circut.
Our old system was oversized by todays standard (32kW), so we went along with adjustable 20kW system. The burner output can be set between 18 and 23kW. The system uses a one piece burner housing and condeser unit unlike others.
We ordered the system in September last year, but were told that it won't be installed until this spring. My mum of instantly looked at the man and said: „You know what will happen? On Christmas we'll sit here without any heating!" "If that happens, I will take care of that situation! Take my word!" he said.
25.12.2014: My mum stands beside the technician in our basement, shows him the not runnig system and says: "So, go ahead and take care of it!" He got to start it again, but 2 days later, it finaly gave up. He managed to construct a system that consisted of 3 bricks, several pieces of wire and some sheet metal to attach a different burner assembly. One just had to touch it a bit careless and that room would probably have gone up in flames. Though, he did not bill us anything for anything. That's what I call customer service.
So, they called last week and said they'd start installation today. They came a bit late, but were done with todays work by 4pm. Today, they took out the old unit (pictures below) and prepared everything for the next day.
Tomorrow, they will first do a re-regulation of the flow rates. That basicly means they limit the flow of any heating heating circut in this household so that the backflow to the condesation unit can be assured to stay beneath a certain temperature limit (I think about 60°C, 140°F) to ensure proper condesation. Then, the venting will be redone. As the exhaust gases are cooled below 100°C in any case, our jimney is fitted with a big, double walled plastic pipe. The inner pipe is designed to allow perfect airflow while the outer part is used as air intake. Then, they'll put in tank and heating unit and hook them up. On wednesday, they will fill the system up, configure it and check it. So I hope I can shower again on wednesday evening.
I'll keep you posted. If you got any questions, I'll try to answer them.
Best wishes to all of you
Henrik
