Underfloor Heating Setup

[WillC1423]

Hello all,

I've received several underfloor heating quotes recently, with the intention of just using them for information and then sourcing the parts and installing myself. I can do it much cheaper that way.

I have one question however. Downstairs is a single zone screed floor with an area of ~34m2 that needs heating. With pipes at 200 centers that'll be approximately 170m of pipe. I've read in several places that it's not recommended to have more than 100m of pipe off one port, I'm assuming this is because of the temperature drop over the length of the pipe. How are multiple pipes normally setup?

If I use multiple ports, then we're going to need multiple actuators linked to a single thermostat, which seems like a bad idea to me. It makes more sense to me to just fork the pipe with a T connector just after it leaves the manifold and increase the flow rate accordingly. Would this be the normal way to do it? I can't see any downside to this as the flow is all provided by the same pump whether it be multiple ports or a T connector.

 

[WillC1423]

A bit more info. They are wavin parts that I'm looking at. And going through the 'quick calc' on their website, for the downstairs system they suggest a 2 port manifold, I have just noticed it also suggests a 230v thermostat and no actuator. So I'm guessing that the thermostat links to and fires up the pump rather than opening and closing ports?

Is this assumption correct?

 

[JayPage]

The issue with long runs is usually sorted by adding another zone and thermostat to the same room if it's very large or as you stated having the room stat open up two ports. The problem you might have teeing off of a single zone is the flow rate, as this is very important in ufh. Ive installed quite a few myself and seen many more installed by sub contractors and have never seen a tee added to a single zone. It's a little naughty to call upon a company's time with no intention of ever using them if you ask me!

 

[ServiceNumpty]

Agreed with above, 2 port manifolds is the way to go.

 

[Salmonfisher]

I've received several underfloor heating quotes recently, with the intention of just using them for information and then sourcing the parts and installing myself. I can do it much cheaper that way

Read more: //www.diynot.com/forums/plumbing/underfloor-heating-setup.354351/#ixzz2K9xvKwt0

Another time waster

 

[RickMoore]

And did you pay for the quotes, or did you just waste the time and money of the people quoting, knowing full well you had NO intention of taking up ANY of them to do the job ?
Saving yourself money is fine, but don't do it at the expense of others, you may as well just take money right out of their pocket, it amounts to exactly the same thing.
I will give you the answer YOU deserve though, save your self a packet and forget the manifolds and controls, just T right into the flow and return off the boiler and run the pipe around the room, the longer the circuit the better.

 

[WillC1423]

Thanks for the constructive replies - I found some wiring diagrams buried on Wavin's website which detail the setup they suggest linking the thermostat to a motorised valve and the pump, and then have the multiple port manifold.

With regards to those stropping about quotes, I was originally considering using a company, but the online quote came in a lot more expensive that I'd hoped. I then started looking at sourcing the stuff myself and came across Wavin's system at good value. I then called Wavin for information about the system design, saying I was looking at purchasing their system from elsewhere as it would be cheaper than them supplying it. They requested that I let them do a quote saying they'd give me a discount - as I suspected, it still wasn't as cheap as me sourcing the stuff. So I'm sourcing it from elsewhere. I also did a few automated quotes, which obviously don't take up anyone's time. Wavin are still getting my money as they're manufacturing the goods - they just need to learn to price match to their re-sellers!

It's not like they do any more than plumb some numbers into a system for some heat loss calculations and then an estimate the amount of pipe needed. I've not requested pipe layout designs or anything, or got anyone round the house!

So maybe my original post wasn't totally clear, but chill out people. If a company offers free online quotes they'll get requests from people with very little intention of using them.

 

[ServiceNumpty]

Thats fair enough mate,we understood you to have had installers out to survey, speccing an underfloor system as your finding out is a time consuming affair, even though professional installers are quicker than yourself.