Renovate underfloor heating in a 20-year-old house

Hello everyone

We have bought a 20-year-old house. Recently, I saw a report on television saying that you cannot trust underfloor heating systems older than 20 years.

Above all, plastic pipes are very susceptible to oxygen diffusion. I have heard of the company LSE System. Has anyone of you had experience with this company?

In the HAT process, the pipes of the underfloor heating are cleaned and then coated internally with a new layer, so to speak, a pipe within a pipe. However, this renovation costs CHF 25,000.

Are there cheaper alternatives? For example, only removing the sludge from the pipe? Or is the problem just postponed by that?

If the pipes are defective, is replacing the pipes or tearing up the entire floor the only option left? Or is it possible to somehow shut down the underfloor heating and install cost- and effort-saving options like low-temperature radiators?

Thank you very much for your feedback!

The whole thing from me is now non-binding!

I think cleaning the heating system from dirt is possible with a 'flush through,' the effort is not too great.

But the main problem, as mentioned, is probably the pipes, which naturally become more porous over time and with hot water. But I wouldn't do a radical renovation yet. Let a professional check the pipes first?

I also misunderstood something about the flow.

Heating Water Analysis

I am a neutral heating water technician; unfortunately, I have to inform at least 4-6 owners per week about the facts of underfloor heating.

The fact is, there is no widespread damage to underfloor heating pipes.
It makes no sense to apply an internal pipe coating to underfloor heating pipes, as oxygen also penetrates through the internal pipe coating!
The aging behavior continues regardless with an internal pipe coating!

The aging behavior of plastics is influenced, besides the properties of the plastic itself, by time, temperature, pressure, and the composition of the transported medium.

However, the durability of the pipes is mainly affected by the effective duration of the stabilizers contained in the plastic. To put it bluntly, these additives live less long than the carrier material, the plastic. The material ages, becomes less elastic, therefore brittle. Especially older underfloor heating systems, which have been operated with comparatively high supply temperatures (around 60° to 70°C), age much faster than low-temperature systems, as are common in new buildings today.

What does this effect mean for the registers of underfloor heating? And here some clear relativizations are in order:

Pipes for underfloor heating consist of polyethylene (PE), especially cross-linked polyethylene (PE-X), polypropylene (PP) – including copolymer polypropylene (PPC) – or polybutylene (PB, also referred to as polybutene).

Second: In a statement by EMPA, assuming system-specific and correct dimensioning of the systems, a service life of 50 years is mentioned. The standards also assume this service life. The SIA suggests 30 years as the calculated service life of an underfloor heating system. For these time periods, the mentioned embrittlement effects are completely uncritical.

Conversely: The aging process of the plastic until a leakage occurs takes much longer than the underfloor heating system lives. Conclusion: Underfloor heating pipes tend to become brittle but generally do not cause damage.

Maintenance and care of an underfloor heating system:

Homeowners should have a heating water analysis performed annually. If the values comply with VDI 2035 Part 1 + Part 2, the interval can be extended to 2-3 years.

A heating water analysis must be carried out professionally correctly, that is, with accredited measuring devices and by a trained specialist.

The analysis must be strictly neutral; it must not be performed by a provider dependent on a product.

An understandable interpretation of the measurement values and a comparison with the guidelines are required so that the customer knows exactly what the situation is and what, if anything, needs to be done.

Best regards