Underfloor heating - Maintenance advise
 

I'd be interested to know if anyone here - or looking in from other forums, would know anything about periodic maintenance on underfloor heating. Particularly in regards to bleeding air from the system and/or flushing of the manifolds and pipes.

Mme TP has been talking to someone (the bin-men?) and has come up with the idea that time is overdue to get the system checked-over/maintained.
I'm a firm believer of the old adage 'if it aint broken, why fix it'. The system appears to function as it should. It's gas-fired water heating, from a Bosch boiler installed 4 years ago, and heats all rooms adequately underfloor over an area of 125m2.

The system has never had any maintenance over the 12 years we've been here, or to the best of my knowledge the 10 years prior to that.
The bin-men (or whoever) suggested that sludge may possibly build up within the manifolds and pipework, and lead to the system being less efficient.
I've checked on a few websites which state that, 'Maintenance is possible, and the pressure of the system should be checked, bled and flushed now and again'. Another says, 'Systems should not need any maintenance carried out upon it whatsoever for the entirety of its life. Inhibitors are used to stop any build of sludge in other parts of the system'. Which is all rather confusing.

I called our plumber (the same who performs the annual check on the boiler) to get his advise. He said in view of no maintenance over 20+ years it may be wise to give it some thought, but didn't enlarge further.
Any thoughts on this, pros or cons?

Re: Underfloor heating - Maintenance advise
 

Hi TP. My old system had a filter and when it started to clog up more than usual on its annual check, I was advised to have the pipes flushed and refilled with new fluid. This made sense to me as the debris I would expect came from scaling in the system and perhaps replacing once every 4 years or so would prolong the life of the pump etc. Obviously the cost would be a deciding factor.

Having said that, the manufacture of my car, recommends replacing cooling system fluid every so often. Cannot remember the interval because it is something that I have ignored.

Good luck.

Re: Underfloor heating - Maintenance advise
 

Audio, many thanks for your feedback.

The little lady tells me that she asked a similar question about 'le desambouage' to another visiting plumber some 5 years ago, who then gave an estimate of 800 euros for cleaning and flushing the system.
I wasn't told about that at the time as she probably realised she'd be bound - and especially gagged - with further questions of that nature. Amazing isn't it, that something like an underfloor heating system, functioning perfectly, which is completely out of sight, is far from out of mind with those of the fair sex. I think with her it's a case of, "I'm worried, 'cause I've got nothing to worry about!" Don't you just love 'em?

Our current plumber, an excellent worker, for a large, well established local company, gave an estimate of 500 euros.
Methinks that Mme TP should be served a restraining order, as she may just be wanting to make a dent in my Pomerol, Medoc and Saint-Emilion savings funds. Perish the thought!
But as it's Valentine's day today, and I do feel for her, I may just give her concerns a little extra thought over a glass or two of Chateau Beauregard, avec moderation bien entendu......

Re: Underfloor heating - Maintenance advise
 

Hi TP
Can't answer your specific question but I recently replaced by boiler in the UK.
In the UK, it is a requirement to flush the entire heating system when a boiler is replaced.
It was a simple process of attaching a separate pump to the system in place of the normal heating pump (in parallel) and running it until the water ran clear.
It took a couple of hours.
The system was then filled with inhibitor to prevent sludge.
My pump has a magnet to catch any metallic sludge.
HTH

Re: Underfloor heating - Maintenance advise
 

Just had my gas boiler changed and had the option to do the "desambouage" at the same time for an extra 800€ or so on the basis that if the boiler pump clogs up due to dirt in the system it won't be covered by the warranty. This is meant to pump acid through each radiator in turn (not underfloor heating here) to remove any sludge and limescale but this can also cause leaks at joints on older systems where the dirt is helping the seal. I didn't do it in the end on the basis that it hasn't been done for over 20 years and hadn't ruined the boiler in that time, but I did get a filter installed to catch any big bits flowing around. The water did flow black during the boiler changeover but probably not a real issue, fingers crossed. So I would say its up to you if it makes your mrs sleep better at night. The concept of worrying that there is nothing to worry about does ring true in this house as well!

Re: Underfloor heating - Maintenance advise
 

If there is no filter in the system and assuming that the pipe is a standard plumbing pipe (as used for domestic water supplies) and that the pipe is accessible before it goes under the floor, then you could install a replaceable cartridge filter like the one shown here. As it has a clear canister you can easily see if the filter is catching sludge or particles. I use a similar filter for my water supply, and the replacement filter only costs a few $$$ - it looks like a thin roll of paper kitchen towels.

Re: Underfloor heating - Maintenance advise
 

Cyrian / SB / Jeremy Pulaski,
Some good info you've all provided as food for thought, so many thanks.

Re: Underfloor heating - Maintenance advise
 

Your instincts are correct TP - don't touch it. The underfloor heating is almost certainly in polypropylene pipes and it is a closed system so whatever liquid is in it (possibly just plain water) will be inert by now. Unless you have a small leak and have to re-pressurise frequently then there is little point in draining and re-filling. I guess in very cold climates there is a risk it could freeze if the property is left unoccupied and therefore some anti-freeze might be required.

Re: Underfloor heating - Maintenance advise
 

Re: Underfloor heating - Maintenance advise
 

IVV/Dfj, many thanks for the additional feedback.
Following all the above comments and a general discussion, a 'relative' peace reigns in the household - at least for the moment........(takes a deep breath). I put my foot down with a firm hand.:p
Having said that, this morning after another brief discussion I could hardly believe what I'd just heard, "Well anyway, I think it might be time to change the wall-mounted central heating thermostat!":mad: (You guessed it, it's functioning perfectly).
There's one thing here however that may need changing soon. Heaven forbid that my next post is not for the recommendation of a divorce lawyer in the S.W. She definitely doesn't deserve to loose me.......wink, wink.

Re: Underfloor heating - Maintenance advise
 

While I am sympathetic to the "if it ain't broke, don't fix it" philosophy, I am not sure that "don't do anything until it is broken" is the best plan. If there is any sludging in the pipes it would be better to deal with it before you have a crisis. Similarly if there is any degradation of the pipes. I don't know about in France, but in the US before polypropylene pipes there were polybutylene pipes that are known to degrade under some circumstances, and personally I would want to know if the underfloor heating was degrading before there was a catastrophic failure. :unsure: