ᐅ Old gas heating system broken – need a new one, but what kind?
Created on: 11 Feb 2020 07:34
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Nissandriver
Good morning,
we bought a house that was built in 1936 and renovated in 2013.
Last year we viewed it and decided to buy it. Considering that the heating system dates back to 1997, we thought we would need to replace it “soon.”
House: approximately 145m² (1,560 sq ft) of living space, insulated roof, thick exterior walls. Double-glazed windows, chimney in the living room.
The chimney sweep wanted to shut it down two weeks ago because there was a strong smell of gas in the basement. Since we keep the windows open downstairs and have two small children, he decided against it. On his recommendation, we should get a new heating system because repairing the current one would be a waste of money.
We have now had four different heating companies inspect the house. The discussion came up (because I wanted to explore alternatives):
Since we currently have a 27kW (36 hp) instantaneous water heater in the basement for hot water, the question is whether that should be removed and the new heating system used to heat the water as well.
We are planning to install a 10 kWp photovoltaic system on the roof anyway.
I know this is a personal decision, but I would like to become a bit more independent from fossil fuels.
I hope you can help me a little!
Best regards
we bought a house that was built in 1936 and renovated in 2013.
Last year we viewed it and decided to buy it. Considering that the heating system dates back to 1997, we thought we would need to replace it “soon.”
House: approximately 145m² (1,560 sq ft) of living space, insulated roof, thick exterior walls. Double-glazed windows, chimney in the living room.
The chimney sweep wanted to shut it down two weeks ago because there was a strong smell of gas in the basement. Since we keep the windows open downstairs and have two small children, he decided against it. On his recommendation, we should get a new heating system because repairing the current one would be a waste of money.
We have now had four different heating companies inspect the house. The discussion came up (because I wanted to explore alternatives):
- Gas condensing boiler – a gas connection is available, it would be cheaper but is not subsidized (due to CO2 taxes, depending on gas prices).
- Pellet heating – mixed opinions – one expert said it wouldn’t work in the basement due to high humidity (another specialist said that’s nonsense) – higher initial costs – pellet prices are similar to gas prices and it is subsidized up to 35%.
- Log wood stove – high initial cost, needs to be refueled by hand regularly – no clear information on subsidies.
- Air-to-water heat pump – subsidized, the heating specialist took measurements of every single room including ceiling height to calculate the heat demand for the whole house and size the heat pump accordingly. He said he has good experience with it – but electricity prices will rise… it would also need a higher seasonal performance factor to be worthwhile.
Since we currently have a 27kW (36 hp) instantaneous water heater in the basement for hot water, the question is whether that should be removed and the new heating system used to heat the water as well.
We are planning to install a 10 kWp photovoltaic system on the roof anyway.
I know this is a personal decision, but I would like to become a bit more independent from fossil fuels.
I hope you can help me a little!
Best regards
N
Nissandriver11 Feb 2020 14:31T_im_Norden schrieb:
So, a new heat sink like underfloor heating, windows, insulation, or a new heating system.
The energy consumption of your house is relatively high.
Regarding heating, check the BAFA website for gas hybrid heating and related subsidies. If everything fits, you can get up to 35% of the costs covered for a boiler plus solar system for hot water.
Depending on what you do, even a new underfloor heating system and the necessary work can be subsidized up to 35%. OK, thanks for the information. I hadn’t considered a gas hybrid heating system yet, but I will look into it.
I am also planning to insulate the basement ceiling, but it is slightly curved, so I still need to get more information about that.
The windows were installed in 2013, and the exterior walls are not insulated because the walls are quite thick.
N
Nissandriver3 Mar 2020 08:22Good morning,
I have now gathered several quotes.
It is surprising how the statements from the heating companies vary..
For example:
Out of 6 companies, only one actually took a closer look at the old heating system and cleaned it again -> the gas smell dropped dramatically
The others more or less made a “remote diagnosis”
The decision is not easy.. Either become more independent with the photovoltaic system and go for alternatives or fully rely on fossil fuels again (alternatively on bio-gas)
We are planning to have a photovoltaic system installed anyway. (9.9 kWp)
I have now gathered several quotes.
- Gas condensing boiler with hot water heat pump (for the basement with dehumidification) ~ 10,000 - 11,000€ (including installation and materials, etc.) (Buderus and Weishaupt)
- Heat pump with hot water heat pump (including installation and materials, etc.) ~ 26,000€, but this is subsidized with around 9,400€. The heating contractor asked for the square meters of each room + ceiling height and what is installed where -> from this, he made the calculation
- I haven’t received an offer for a gas hybrid heating system yet..
It is surprising how the statements from the heating companies vary..
For example:
- Remove everything, install a new gas condensing boiler, electric instantaneous water heater stays
- Remove everything, install a new gas condensing boiler, hot water will be provided by it
- No alternatives available
- All nonsense about alternatives (even though they advertise this on their website oops 🙂 )
Out of 6 companies, only one actually took a closer look at the old heating system and cleaned it again -> the gas smell dropped dramatically
The others more or less made a “remote diagnosis”
The decision is not easy.. Either become more independent with the photovoltaic system and go for alternatives or fully rely on fossil fuels again (alternatively on bio-gas)
We are planning to have a photovoltaic system installed anyway. (9.9 kWp)
Gas condensing boiler plus domestic hot water all-in-one and ready to go (I would completely avoid photovoltaic systems and similar setups – they just make everything unnecessarily expensive and you will never recover the costs).
I don’t quite understand the hot water heat pump part:
"Domestic hot water heat pumps can, for example, use air from basement rooms, which in winter months have a constant and relatively high temperature. The temperature in the basement room is lowered by the heat pump by about 2-4°C (3.6-7.2°F)."
At the same time, the basement air is dehumidified."
Which basement actually has a constant relatively high temperature in winter? Also, doesn’t the basement get cooled at the same time? And with a cold basement, wouldn’t there be condensation problems? – that does not sound logical to me at first glance.
With the new system and replacing the instantaneous water heater, you will already be somewhat "more environmentally friendly"… even if it is powered by biogas…
I don’t quite understand the hot water heat pump part:
"Domestic hot water heat pumps can, for example, use air from basement rooms, which in winter months have a constant and relatively high temperature. The temperature in the basement room is lowered by the heat pump by about 2-4°C (3.6-7.2°F)."
At the same time, the basement air is dehumidified."
Which basement actually has a constant relatively high temperature in winter? Also, doesn’t the basement get cooled at the same time? And with a cold basement, wouldn’t there be condensation problems? – that does not sound logical to me at first glance.
With the new system and replacing the instantaneous water heater, you will already be somewhat "more environmentally friendly"… even if it is powered by biogas…
T
T_im_Norden3 Mar 2020 08:47Be sure to visit the other forum (the red one) and get advice there. Have all the information about your house ready and include details such as wind load, insulation, windows, and energy consumption.
When it comes to heat pumps or heat pumps in the basement, all my alarm bells are ringing at the moment.
When it comes to heat pumps or heat pumps in the basement, all my alarm bells are ringing at the moment.
T
T_im_Norden3 Mar 2020 08:49Photovoltaic system Please note that the cover has not been lifted yet; it is possible that there is no guaranteed feed-in tariff.
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Nissandriver3 Mar 2020 08:59Basti2709 schrieb:
Gas condensing boiler + domestic hot water all in one and done (I would completely skip photovoltaics and such gimmicks – they just make everything unnecessarily expensive and you will never get that money back).
I don’t quite understand the domestic hot water heat pump part:
"Domestic hot water heat pumps can, for example, use the air from basement rooms, which maintain a constant and relatively high temperature during winter months. The air temperature in the basement is lowered by about 2–4°C (4–7°F) by the heat pump."
At the same time, the basement air is dehumidified."
Which basement has a constantly relatively high temperature during winter? Also, doesn’t the basement get cooled at the same time? And wouldn’t a cold basement cause condensation problems? – To me, this doesn’t sound logical at first.
With the new system and replacing the instantaneous water heater, you will already be more “eco-friendly”... even driven by biogas if you want... You can’t recover the investment in a photovoltaic system anymore? I’ve read different things in various forums (although you should avoid using a battery).
If the heating system (old gas boiler) is located in the basement, it also emits heat. How much, I can’t say.
T_im_Norden schrieb:
Definitely go to the other forum (the red one) and get advice there.
Have all the details about your house ready and include them, such as insulation quality, window types, consumption, wind loads.
Heat pumps, especially basement-located ones, set off all my alarms at the moment. Okay, I’m on it! I’ve already read about domestic hot water heat pumps in the other forum. But I will ask specifically again.
T_im_Norden schrieb:
Regarding photovoltaic systems, please note that the feed-in tariff cap has not been lifted yet; it may be that there is no guaranteed feed-in tariff. I had a conversation with the colleagues yesterday. They said if it still goes through by March, the feed-in tariff will be 9.87 cents/kWh for the next 20 years. But I will look into it further.
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