ᐅ Old gas heating system broken – need a new one, but what kind?

Created on: 11 Feb 2020 07:34
N
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):
  • 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
T
T_im_Norden
11 Feb 2020 09:49
Do you have an annual consumption value?
N
Nissandriver
11 Feb 2020 09:58
T_im_Norden schrieb:

Do you have an annual consumption value?

Unfortunately not, we didn’t receive one from the previous owner.
I calculated that we are currently using about 110 m³ (3,888 cubic feet) of gas per day. I should also mention that my wife is still at home right now because of the baby. She will return to work in April.
T
T_im_Norden
11 Feb 2020 10:05
You should have received an energy performance certificate.

110 m (360 ft) according to the gas meter?
Mycraft11 Feb 2020 10:05
You need to address this urgently; your system is simply venting the gas straight into the chimney. This is already life-threatening.
H
halmi
11 Feb 2020 10:10
That already sounds quite challenging... without underfloor heating, gas will probably be the only practical option.

Perhaps have a calculation done to see the costs for an air-to-water heat pump plus new low-temperature radiators minus the subsidy. But it’s best to get an offer for the air-to-water heat pump from a different company.
N
Nissandriver
11 Feb 2020 10:11
T_im_Norden schrieb:

You must have received an energy performance certificate.

110m according to the gas meter?

Yes, according to the gas meter. There are no values listed on the certificate itself (i.e., no consumption data).
The energy certificate states:
  • Final energy demand: 201.7 kWh / (m²*a)
  • Primary energy demand: 234.1 kWh / (m²*a)
  • CO2 emissions: 56 kg / (m²*a)
Mycraft schrieb:

You need to take action immediately; your system is just sending the gas straight up the chimney. In other words, that’s already life-threatening.


We’re working on it!