Currently we have ufh (5 zones) powered by expensive lpg, which will increase to seven after some building work. I'd like more control of the system and believe fitting actuators on the manifold would be the way forward. My question is what would a system to control the seven actuators look like? I'd presumably need 7 thermostats - one in each room...

Flow and return manifolds yes and the manifold is full, I control the heat by restricting the flow to bedrooms for example. The thermostat digital RF I keep in the bathroom (smallest room).

There's a digital thermostat in one room - the bathroom. The bedrooms which need to be cooler and kept low temperature by restricting the flow of warm water through the manifold.

Here is what we've got - basic set up. Either we break into the existing loops and extend into new add ons (porch and sunroom) or we lay new loops and add to the manifold. Don't know how feasible adding new loops is

Whether you run new pipes to your new work will depend on whether you can get a run to them from your manifold.
If you cannot lay in the floor i.e in a screed than there is an option of an overlay system as suggested by Simon.
Either way it looks like you will need a new manifold arrangement. You can get them made up and tested with a mixing valve and circulating pump. My system is configured like that each loop has an actuating valve and stat located in the room being controlled. Don't know how practical it would be but you could tee into a current loop(s) and it looks like your current valves are capable of getting actuators fitted so that could be something you could do to upgrade what you have. There is a rule of thumb that loops should not be longer than 100m for 16 mm pipe might be different for other bores. There are many suppliers out there I used Robbens system the website has lots of info and their stuff is quality. You may get some ideas from there, there are many layouts of laying pipe in different scenarios. Their technical staff are very helpful.

<blockquote><cite>Posted By: Simon Still</cite>Next questions

- what is your floor build up (is this into concrete/screed or an overlay system)?
- is the flow to the UFH at a fixed temperature (and if so what's it set at) or variable?

How well insulated is the house? You mention a porch and sunroom - those don't sound like they're going to be the best insulated spaces.</blockquote>

The house is insulated with 150mm celotex in walls and roof. We have ufh laid in concrete +screed floor with celotex laid underneath and triple glazing

The porch/utility room and sunroom will be built to current regulation standards.

Thanks Dairmid for the floor plan.

As above, would need to know:

- where the sunroom and porch are to be added (don't think they are on this drawing? This I assume is the "existing" floor plan. Do you have a "proposed" floor plan?)

- position of boiler, pipes to the manifold, ufh pipe routes (approximately) so it's clear which loop covers which area, eg. is the hall part of the bathroom loop??

Hi Dairmid, our messages crossed

You "could" T off the existing loops, but the loop length may well be an issue. You don't need huge lengths of pipe in each room, as your 150mm kingspan and 3G windows will take your heat loss down to low values. However, the existing UFH may have been laid at say 100mm centres, as installers are often very conservative, or may have been installed pre-IWI, when heat losses were much higher.

Also, that would mean you would have the kitchen/util as one zone, and lounge/sunroom as one zone. Kitchen and lounge have their own heat sources (cooking/stove), whilst sunroom and utility will be higher heat loss room (external walls and larger window areas).

These points all make it much more difficult to get any decent control over room temperature, and may be an issue with pipe length/pressure drop/flow rate.

I assume you have a bungalow, so running pipes in the attic would be straight forward. I think, based on what I've seen, I would design it as follows;

- add a pump and therm mixing valve at the existing manifold, so you are properly controlling floor input temps, and not excessively running the boiler and at high temps. (can be individual pump and TMV or a pre assembled unit)

- take a copper F/R into the attic from the F/R at the manifold (could be on either end of the manifold) which would then split to feed the sunroom and utility separately.

- The feed to these additional rooms would be controlled by a single straight solenoid valve which takes an UFH actuator to match the ones you would add to the existing manifold (effectively a mini single manifold at each of the 2 new rooms). eg.... https://underfloorparts.co.uk/product/15mm-straight-solenoid-valve-underfloor-parts/

- add a wireless room stat in each room (or zone - might combine kitchen and lounge as open plan for example) which talk to the actuator controller (something like this... https://underfloorheating-direct.com/heatmiser-uh8-wiring-centre-26402-p.asp, with a room stat like this ... https://underfloorheating-direct.com/heatmiser-slimline-rf-26446-p.asp

The above are examples of types of equipment that I've used many times, and work well, but shop around and look for better prices.

Get a design on paper, think it through carefully, then proceed. Don't try to wing it with some thoughts or verbal discussions.

Cheers, David.

Posted By: GreenPaddysunroom and utility will be higher heat loss room

That's true but the sun room should also be a higher heat gain room on sunny days! Very difficult to match with other rooms.

Posted By: Diarmidupdate: quote to install ufh astronomical given the small size of the rooms we're adding. Mulling over options - what are they? electric UFH?

What's astronomical? What drives the cost? UFH 'kit' shouldn't be that expensive (recommend Wundafloor for value). and installation doesn't take that long to DIY.