Especially when you don't have the "house manual" ...
We therefore put our heated floor installation back into service by proceeding as follows:
a) complete emptying
b) washing the circuit by injecting mains water in order to clear the circuit and especially the loops
c) draining the washing water (loaded with sludge)
d) re-pressurizing the circuit, starting the circulator
e) floor / floor opening / closing (starting from the highest, or rather farthest from the circulator) to expel the air
We stabilized the pressure at 2 bars ...
Steps b) and c) were repeated as many times as possible, in our case a good ten times.
In terms of maintenance, I found this on the net (but it does not only concern PCs):
http://perso.orange.fr/bernard.pironin/ ... ecbt01.htm
a) Pathologies.
For this type of circuit, the pathologies are those linked to corrosion and its consequence: the sludge of the networks.
It is also possible in the case of frequent supply of unsoftened water a risk of scaling which due to the temperatures reached locally - in generator - will be systematic (if the local temperature of the water goes above 80ºC we have decomposed bicarbonates which lead to the formation of carbonates) and cumulative if the water has a non-zero TH and that additions are made.
However, the first risk of sludge is linked:
For circuits made of "black" steel with the presence of scale which will detach from the walls upon the first heating and will form sludge; We cannot stress enough for these networks the need to carry out a rigorous cleaning before putting into service with a detergent.
It must be possible to recover this sludge in capacities specially designed for this purpose. For this, we can use distribution bottles - hydraulic separation or a "sludge pot"; this should be supplemented by drain points at the bottom of each column. It should be remembered that the "black" steel tube owes its name to its appearance: produced hot iron reacts with oxygen to form black iron oxides called scale.
For all circuits with the presence of manufacturing waste, materials introduced during manufacturing - brazing flux, filings, foundry sand -, foreign materials related to storage and handling - sands, plaster, cement, dead leaves, … The waiting pipes must be plugged, systematic removal of foreign bodies, ensuring that the storage of waiting parts is carried out free from contamination,…
Mention may also be made, in the case of “grids” of heated floors, of the risk associated with the use of dirty water (“the mason's water barrel”) during pressurization operations for testing and coating the tubes. In the case of "grids" the use of an antifreeze, which may be necessary during work in the cold season, must be checked: this can "turn vinegar", and should be removed after work if it does not. is not necessary.
This detachment of the scale can be explained by the fact that these ferrous oxides react with the oxygen in the water to form ferric oxides whose volume is greater. This swelling leads to detachment; these oxides then react in the absence of oxygen to again form ferrous oxides which will be found in suspension in the water of the networks.
b) Treatments.
The characteristics of this type of circuit, the materials used and the physical conditions lead to deduce from it the precautions to be taken and the additional water treatments.
We must make the cleanest network possible:
* Ensure the storage of tubes and equipment on unsullied areas; systematically eliminate all manufacturing waste and seal the openings of the tubes and equipment on standby;
* After cleaning, carry out a cleaning of the networks with a leaching solution adapted to the materials encountered: this leaching will be followed by draining and prolonged rinsing; Note: leaching will remove particles that will form sludge (scale from steels and cast iron) which can be trapped in vases located on the returns - the hydraulic separation bottles can play this role.
* Filtration equipment is recommended after the first washings; some also have "magnetic filters" which can capture magnetizable oxides (black ferrous oxides).
* We must be able to control the back-ups: systematic installation of a counter;
* The exhaust of the air during filling and the degassing of the water during reheating must be able to be carried out easily: automatic isolating purge for changing the trap coupled with a manual purge at any high point (obstacle passage; distribution bottle - hydraulic separation).
* The water must not be able to provide salts liable to create scaling: softening on resins.
* An oxygen reducer can be used provided:
- That it is compatible with DHW production by simple exchange if this is the case (the highly toxic hydrazine is excluded for example in this case - generally it is not used for collective heating circuits );
- That it cannot lead to bacterial corrosion (case of sulphites in very low temperature circuits which can be "fuels" for corrosion by sulphate-reducing bacteria).
Do you have hydrazine?
