ᐅ What to replace an oil heating system from 1989 in an old, characterful house with?

Created on: 9 Jan 2021 14:19
M
meowmeow
Hello dear forum,

we have an old timber-framed house in the Alpine foreland. Built around 1910 with an extension from the 1960s, the original building has a basement, the extension does not. The insulation is rather poor, and the windows are either double-glazed or old. A hailstorm completely destroyed our roof, so a new roof with good insulation has now been installed.

Currently, we have a Viessmann oil heating system from 1989 with a 2000l (528 gallons) oil tank in the basement, which has caused no major problems so far. The hot water is also centrally supplied by this system. With the old roof, we used about 1900-2500l (502-660 gallons) of oil in winter, depending on the season. With the new roof, we don’t have experience yet, but I expect some improvement. The house has about 115m2 (1238 square feet) of living space, heated by radiators.

Since the heating system is getting old and there are currently larger subsidy programs, we are considering modernization. From my research so far, a heat pump seems to be out of the question because we would need a better-insulated house and underfloor heating? Other types of electric heating seem even less economical?

The least invasive option would probably be a new condensing oil boiler, but these are not subsidized, so I could just wait until the old one breaks down?

A pellet heating system seems too complicated to operate? My mother will soon be 70 and often lives alone in the house. In her old age, I don’t want to put too much strain on her. We frequently visit with our child for several days, but mostly in summer. Also, the long transition phase with low heating loads appears to speak against a pellet system.

I can’t really estimate the costs for gas. A gas connection might be possible with the local supplier if the neighbors join in. We would need about 60-70m (197-230 feet) of gas pipeline on our own property. What costs should I roughly expect? Alternatively, a tank could be buried in the garden, but we are not very enthusiastic about that idea. We are somewhat confused by current politics: on the one hand, fossil fuels are supposed to become much more expensive to promote renewable energy, but on the other hand, gas condensing boilers are heavily subsidized?

For sentimental reasons, we could imagine installing a water-bearing wood stove in the living room. We already have a wood-burning stove in the kitchen where we occasionally cook, and which also provides some heating in winter.

However, it would have to connect to the same chimney currently used by the oil heating system – or the future gas heating system – and from what I understand, this is not allowed, so I might have to give up that dream, right?

We are considering a photovoltaic system on the roof, but we plan to remove the attic floor and renovate the upstairs room within about 5-10 years to get higher ceilings. This would also include adding a few skylights. I should probably wait for these renovation measures first.

What would you recommend? How should the new heating system be sized – I assume this can be calculated quite well based on previous energy consumption?

Thank you very much for your time and help!
J
Joedreck
9 Feb 2021 19:19
You could use bivalent heating. Keep the old heating system and use it for example from -2°C (28°F) and below. For temperatures above that, use a heat pump, for example the Panasonic one that a user here has.
M
meowmeow
9 Feb 2021 19:25
Hmm, I would prefer a wood-burning stove in the living room to support the heating system. A heating technician estimated the cost of a new oil heating system at 20,000 euros. The heat pump would probably be significantly cheaper. I am currently estimating about 8,000 euros for materials and 8,000 euros for installation, removal, and disposal. When it needs to be replaced in 15–20 years, the effort should be manageable. With the difference, I could already cover quite a bit of heating. Ideally, if my system is still eligible for subsidies, the difference would become even greater.

I would then invest the saved amount directly into photovoltaics, better windows, improved radiators, and possibly some insulation to ideally increase the overall comfort and value of the house.

Warenkorb mit zwei Artikeln: Wärmetauscher-Speicher und Panasonic Aquarea; Preisübersicht.
N
nordanney
9 Feb 2021 19:31
Joedreck schrieb:

For example, the Panasonic that a user here has.
Yep. Unbeatable price/performance ratio. Experience report in 4-6 weeks.
N
nordanney
9 Feb 2021 19:37
meowmeow schrieb:

The heat pump would probably be a lot cheaper.
Go for the monoblock. You can simply connect it yourself to the existing heating pipes.
M
meowmeow
9 Feb 2021 19:41
Hmm, I would have to run the water pipes through the exterior wall to the outside. If the heating then fails during winter, I think that could quickly become quite problematic.
What is the main advantage of the monoblock?
With the split systems, you no longer need an annual leak test.
J
Joedreck
9 Feb 2021 19:53
Tell me, what exactly is included in a new oil heating system for 20,000? That seems SIGNIFICANTLY too expensive to me.