Under Floor Heating - Can you use a timer

Ashfield

Hi,
Just a quick question,
In our new build, we have under floor heating down stairs and rads upstairs,
my electrician has now told me that with this set up, we have to have a constant electric feed to the ufh manifold,
This means that we cannot put the ufh on a timer, ie to come on in the morning for an hour because if the ufh is turned off, the heating ufh will take too long to get back up to a decent heat level,
We have stats in each room, which dont have timers, and i have been told that this is the control panel for each room and when we want to turn the ufh on in each room, we have to just turn up the stats,
Does this all make sense to you?
Bit of a pain in the arse if i cant set my ufh to come on for an hour in the morning before i get up!!
Hope ive explained my problem properly
Thanks in advance
A

sinnerboy

None of that makes sense . Find and pay for expert advice to oversee your works in progress . Do it now before you build an expensive mistake .

read this for general information

http://constructireland.ie/Vol-4-Issue-5/Articles/Heating/The-critical-role-of-heating-controls-in-achieving-energy-efficiency.html


Look for an expert amongst this list ( the ones ticked relative to heating )

http://www.sei.ie/Grants/Home_Energy_Saving_Scheme/HES_Contractors_List.pdf

- not the only place to look- but the most expedient place I can think of

.

L_gaucho

Be cafeful of electricians when it comes to plumbing. They tend to want to take the path of least resistance (bit like elect current really:D).
I had to re-wire my own heating because of this. Your plumber should be able to tell you what options are available, its up to the electrician to make it work.
On the underfloor heating, as I understand it, the pipes are set in conrete, its takes quite a while for the heat to rise to the room. you prob be gone to work by the time you get that heat,
Have you 2 seperate temps for the rads vs underfloor? (rads operate at approx70 deg, underfloor at 40deg).
By the way I 'm not a plumber , just learned quite a bit through my own build.
At the very least though, looks like you need to get the spark and plumber into the same room, and plan the thing out, and get a second opinion.

Poor Uncle Tom

Last October I witnessed one of the best installed heating systems I have ever seen. Ufh in a screed on the ground floor and rads upstairs, simple. But it was the way it was carried out which really impressed me. The new house belonged to the plumber himself and the electrician was his brother.

The main points we all learned were as follows:

i) for the ufh keep as many zones as is practical, kitchen and utility, circulation spaces, dining room and study, living room and sitting room, etc.,

ii) insulate the feeder pipes to the different zones very very well, remember those feeder pipes will pass through other zones, leading to hot spots giving false readings from uninsulated feeder pipes.

iii) avoid putting ufh pipes beneath matwells and the end of the stairs, if the stairs are timber the floor screed heating up or cooling down could lead to some creaking from the stairs.

iv) it takes a while to get used to the controls for the ufh network, instant may be fast in terms of ufh but it is not instant.

v) the screed holding the ufh pipes should be as thin as is practical, should be kept at 50mm if possible, the thinner the screed the faster the heat response time.

vi) insulate thoroughly and evenly beneath the screed and up by the outer walls.

vii) if you are using oil to heat, it will initally take a fill or a fill and a half to 'dry out' as the screed is a wet set as is any plaster work on the inside.

viii) the plumber and electrician need to take as much time as they need to set up the ufh system, it's a job that is not to be rushed, and imo, no other trades should be working on the build during this process. If it goes wrong here you will have problems forever.

Ashfield

Sorry if I was unclear
Ok we have rads upstairs....fine
UFH downstairs
Been told that we need to keep the ufh manifold always turned on,
On the control panel there is a timer for UFH,
If i knock the ufh on the control panel tonight and want it to come on at 7am tomorrow, the ufh wont heat the rooms for a couple of hours as the feed to it would be off,
We have individual thermostats in each room with heat control panels,
Can i get stats for these rooms with timers on them so that i can leave the overall ufh control panel on yet i can time when i want the stats to come on??

sinnerboy

You system should be set up like so

Boiler - pipework from it splits into 3 zones

1. Hot water ( kitchen/bathrooms ) . Must be controlled by a Timer and a cylinder stat ( set to 60 degrees)
2. Rads - must be controlled by a timer and a temp stat - usually in the Master Bedroom
3. UFH - must controlled by a timer ( controlling ALL parts of UFH ) and then individual room or area stats .

The Timers always "master" the stats i.e. a stat cannot demand heat when it's zone timer is set to off .

This by the way is only Building Regulations MINIMUM required level of controls

Your individual UFH room/area stats cannot demand heat when the UFH timer is set to off

UFH is slow response - but it is wrong to say it must be always on . Typically UFH should be timed to start up 2 hours before "wake up" . So if you want to wake up to warm floors at 7am - set Timer 3 to start at 5am

Now you can get UFH stats - which also have a time function . Suppose you only want a warm kitchen floor at 7am - but not the Lounge , untill say 9am . As before set Timer 3 to 5am . Set Kitchen stat/timer to 5am . Set Lounge stat/timer to 7am .

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Joey the lips

Its daft. I use to supply system link uf heating and it could be zoned.