UFH 8 zone Heatmiser System Under Floorboards

[AshleyH]

Good evening all,

 

I was after some advice please. We have an underfloor heating system installed with 8 zones. We are finding it takes quite a long time to heat under on certain zones. 
 

 What operating pressure should the system be at? Ours is currently set to 2 bar?
 

 We are finding that front room is colder than the other rooms, the UFH is installed under floorboards in the insulation boards supplied, ontop of the floorboards we have tiles and wooden flooring. Is this right? Will the heat travel through this many layers? This is what was recommended at the time?
 

Also what should the pump setting be set at? There are serval settings which can be selected from the front of the valve?

 

Without leaving the UFH on all day being controlled by the thermostats it does take quite a long time to heat up? I’ll forward on the plans and the photos of you could get back to me that would be great?
 

Cheers Ash.

[ProDave]

2 bar is plenty, that won't make a difference.

 

What you need to do is adjust the flow meters.  Pop the red plastic cap off and the flow meters will rotate in their housing to adjust the flow rate.  What you want to do is speed up the flow rate to rooms that take a long time to warm up, and slow down the flow rate to the rooms that heat up quickly.

 

Be careful, if you unscrew them too far they will come out then things get a bit wet!!!!

 

I don't know if all zones were on when you took the picture but some are flowing at a good rate (flow meter well down) and others hardly at all (flow meter well up)

 

Your temperature is somewhat high, you don't normally need to run UFH at > 60 degrees. You adjust the temperature with the knob below the pump.

[Temp]

17 minutes ago, AshleyH said:

We are finding that front room is colder than the other rooms, the UFH is installed under floorboards in the insulation boards supplied, ontop of the floorboards we have tiles and wooden flooring. Is this right? Will the heat travel through this many layers? This is what was recommended at the time?

 

Ideally you would just have wood flooring. Not floorboards and wood flooring.

 

We have 21mm wood flooring over UFH and it does work but we have found we need higher flow temperatures than expected.

 

Typically we set our programable room stats to 16C at night (aka "set back") and have them increase to 20/21C about an hour before we get up. It takes about that long to warm up the floor and raise the room temperature.

 

[AshleyH]

I thought this we also have ply ontop so no wonder it takes a while to heat up! Guess there’s nothing I can do about that now though? Could we lay flooring and tiles straight ontop of the thermal boards that the pipes lay into? 
 

Thanks for the adjustment info, there was only two zones on at the time, should I run all zones then adjust the cooler rooms for more flow and the warmer zones for less flow? 
 

does anyone know what the pump setting is meant to be set to? There are multiple setting which can be seen in the photo? It’s on the highest most powerful at the moment? 

[PeterW]

What zone valves have you got ..? Wax cap ones ..??

 

Have you got a picture of the loop lengths too ..? Not just the layout ..?

[AshleyH]

Which caps now sorry? Ontop of the manifold outlets? 
 

No I have I’ll have a chat with the design see if I can get them. What will that say what flow rate to send around each loop? 

[ProDave]

27 minutes ago, AshleyH said:

Which caps now sorry? Ontop of the manifold outlets? 
 

No I have I’ll have a chat with the design see if I can get them. What will that say what flow rate to send around each loop? 

The flow meters, the clear plastic things on the top of the manifold.  Each has a red plastic "cap" around it's base.  If you prise those up, they will lift off vertically, and then the flw meters can be rotated to adjust the flow in each loop, they turn within a threaded hole.

 

Your aim is to increase the flow rate to the rooms that take a long time to heat up, and reduce the flow rate to rooms that heat up quickly.  It is a long process of trial and error with the ultimate aim of getting all rooms to heat up at the same rate. 

[AshleyH]

Brilliant thanks, this was with all zones online so I will try and adjust the zones which don’t have enough heat. 
 

 

[AshleyH]

Here are the pipe length and flows. 
 

 

3033REV-3-Ashley-UFH-plans-Design.pdf

[ProDave]

I guess it's the kitchen / diner you are having the problem with?  they seem to run at a much higher flow rate to get more heat out.

[AshleyH]

No it’s the sitting room loop 2 and 3? It says there’s carpet there on the design but we went with wooden floor, also it’s the part of the house without anything built on top? I’ve wound all other loops low now and kept the sitting room loop 3 and 2 up high to see if it makes a difference? 

[AshleyH]

The other zones still seem to be heating up quicker! 
 

 

[ProDave]

I take it each room has it's own thermostat?  I only say that as all ours are set at 20 degrees and we don't get much overshoot.

[dpmiller]

is the setpoint really 30C?

[Nickfromwales]

If you get no luck with balancing what you have, you could change to Salus auto-balancing actuators. 

Link

 

These recognise when warm water returns to the manifold, from each loop, and arrests the flow allowing the others to get more pump potential. So if you have a small loop immediately adjacent to the manifold, that will act like an unwanted bypass ( until the stat in that rooms sees the uplift and signals that’s been satisfied / closes the actuator ), but that’s already going to be too long a wait for the problematic zones to improve significantly. 
Balancing is great if all zones are open simultaneously. If not that goes out the window as the flow dynamics will change with the differing combination of zones open at any one particular time. 
Salus = fit and forget. 

Edited October 2, 2020 by Nickfromwales

[AshleyH]

14 hours ago, ProDave said:

I take it each room has it's own thermostat?  I only say that as all ours are set at 20 degrees and we don't get much overshoot.

 

Yes each room has its own thermostat.

 

3 hours ago, dpmiller said:

is the setpoint really 30C?

 

Only to test its not always set to 30'c.

 

 

3 hours ago, Nickfromwales said:

If you get no luck with balancing what you have, you could change to Salus auto-balancing actuators. 

Link

 

These recognise when warm water returns to the manifold, from each loop, and arrests the flow allowing the others to get more pump potential. So if you have a small loop immediately adjacent to the manifold, that will act like an unwanted bypass ( until the stat in that rooms sees the uplift and signals that’s been satisfied / closes the actuator ), but that’s already going to be too long a wait for the problematic zones to improve significantly. 
Balancing is great if all zones are open simultaneously. If not that goes out the window as the flow dynamics will change with the differing combination of zones open at any one particular time. 
Salus = fit and forget. 

 

Ok do you need another system or does the actuator do it itself? there only trade prices on the link, any idea how much these would be?

 

Cheers.

[AshleyH]

3 hours ago, Nickfromwales said:

If you get no luck with balancing what you have, you could change to Salus auto-balancing actuators. 

Link

 

These recognise when warm water returns to the manifold, from each loop, and arrests the flow allowing the others to get more pump potential. So if you have a small loop immediately adjacent to the manifold, that will act like an unwanted bypass ( until the stat in that rooms sees the uplift and signals that’s been satisfied / closes the actuator ), but that’s already going to be too long a wait for the problematic zones to improve significantly. 
Balancing is great if all zones are open simultaneously. If not that goes out the window as the flow dynamics will change with the differing combination of zones open at any one particular time. 
Salus = fit and forget. 

 

 

Just having a read now, will the Salus auto balancing actuators work with the heatmiser ufh8?

[Nickfromwales]

You need to know if the ones you have operate at the same voltage as the Salus. Wunda tech support are pretty helpful.

If you have the MI’s for the system you have them it’ll tell you there if the actuators are low voltage or 230v. The Salus are 230v IIRC. 

[ProDave]

But if you have a good flow rate and plenty hot water through the loops in that room., and it is still struggling to heat up, no change of actuator will solve that.  It is more likely there is another problem, like excess heat loss from that room somehow?

[AshleyH]

16 minutes ago, Nickfromwales said:

You need to know if the ones you have operate at the same voltage as the Salus. Wunda tech support are pretty helpful.

If you have the MI’s for the system you have them it’ll tell you there if the actuators are low voltage or 230v. The Salus are 230v IIRC. 

 

Im pretty sure they are 230, just to throw this into the mix, the plumber fitted a rad also down stairs with a separate electronic valve, this is wired off the hallway thermostatic so operates when this zone is called for heat, would this make a difference?

 

5 minutes ago, ProDave said:

But if you have a good flow rate and plenty hot water through the loops in that room., and it is still struggling to heat up, no change of actuator will solve that.  It is more likely there is another problem, like excess heat loss from that room somehow?

 

I did read too much flow can be just as bad, I've wound the zone 2 and 3 all the way out for maximum flow, perhaps ill try throttling these back first.

 

The installer did say going through 3 layers (floorboard, ply and the flooring) would reduce the heat but you'd think they'd be hotter than they are, the only other difference is the warm rooms hav tile flooring and the cooler room has laminate, this has underlay also?

[Nickfromwales]

The wooden floors should really have been engineered timber and bonded down, as opposed to underlay and loose fit  

If I mix disciplines then I either put twice as much pipe ( or as close to as possible ) in the adverse areas and standard where there are tiles / bonded floors. In extend cases I fit two manifolds so you can choose the correct flow temp fit each instance. With the mix you have you’ll need the elevated flow temp but that’ll be a bit too hot for the tiled areas. 

[Nickfromwales]

13 minutes ago, AshleyH said:

Im pretty sure they are 230, just to throw this into the mix, the plumber fitted a rad also down stairs with a separate electronic valve, this is wired off the hallway thermostatic so operates when this zone is called for heat, would this make a difference?

Shouldn’t matter at all as the manifold has its own pump and it’s the loops this pump services that were discussing the balancing of.  

Edited October 2, 2020 by Nickfromwales

[AdamSee]

17 hours ago, AshleyH said:

The other zones still seem to be heating up quicker! 
 

 

This is un-related to your problem. But what brand of control system/application are you using? 

[AshleyH]

1 minute ago, AdamSee said:

This is un-related to your problem. But what brand of control system/application are you using? 

Heatmiser neo stat v2, UH8 system, individual room wired thermostat's.

[Wil]

From the Salus website:

 

first bullet point would appear to be a problem for you.

A WORLD FIRST IN UNDERFLOOR HEATING TEMPERATURE CIRCUIT BALANCING & ENERGY SAVING

Each Actuator has two temperature sensors which are clipped onto the flow & return pipes (one on each) of the circuit to be controlled. The Auto Balancing Actuator will measure the temperature sensors and adjust the valve position to maintain a constant 7°C temperature differential between the emitter flow and return pipes.

• Not compatible with Heatmiser thermostats
• Very Low Power, less than 0.5W
• Fast actuator opening and closing times typically 30 seconds....