Manual temperature control

[pacemaker1000]

Sorry no pic yet but my manifold has no temperature gauges and only a manual stopcock between flow and return.

so how do I know how to adjust the stopcock so the cooler return water ensures the correct temperature in the flow?

considering a clip on thermometer and turning stopcock until it’s around 40 degrees?

setting boiler at 40 degrees and turning stopcock off?

thanks

[JohnMo]

Not sure what you mean by a stop cock.

 

The manifold should have a mixer valve and pump, the flow loops each have manual valve or actuator and a flow meter.

 

The mixer valve set that to the flow temp you need.  The manual loop valve, open fully.  Set the flow to the flow required for the loop length.  

 

If all room get too hot the mixer valve temp needs reducing, too cool increasing.

 

Once these are set you can fine tune the room temperature.  Increase flow will give a smaller difference between flow and return and increase heat transfer to room, reducing flow to opposite.

 

 

[ProDave]

Who installed it and when?  I am one that believe a proper system needs a blending valve to regulate the temperature, but like others here i have seen several where that has been omitted, whether to save money or from ignorance I don't know.

 

If it is fed from a buffer tank where the temperature of water in the buffer is regulated it might be okay, and it might be okay from a heat pump that can set a low flow temperature, but otherwise I suggest getting the correct blending valve for your manifold.

[pacemaker1000]

Hi guys,

yes it’s a mixer valve no a stopcock sorry. Wrote that to better describe its physical appearance as can be seen in the new pic.

pump is back by boiler not near manifold and as you can see no temperature or pressure gauges. So no way to know where to set the mixer.?

 

Edited September 30, 2022 by pacemaker1000

[JohnMo]

That's not really a mixer valve, as a proper mixer valve modulates to maintain the flow temp. You would need something like this (first image I found).

 

Your system is relying on the heat source controlled flow temp, so has no real protection from over temperature.

 

[pacemaker1000]

Ok it’s starting to make sense I think 🤔 

back at the boiler there is a 4 way controller I assume is for temperature control see pic. It has five settings and is currently on '0'

It connects to boiler flow, manifold pump, manifold return and boiler return

there is also a temperature sensor zippa tied to the manifold flow.

see pic of temperature control panel and please advise on setting. All my underfloor is in concrete!

 

with this in mind my thought is the original post and pic of control valves on actual manifold , this is redundant and should be fully closed as it interferes with the 'proper' temperature control near boiler as it effectively cools the set temperature in the flow?

I assume it’s located there as I have two manifolds , second one upstairs, and this is able to control both?

 

would be  nice to have a physical temperature gauge to check it is does g what it should. Maybe a clip on one somewhere

 

thanks

Edited September 30, 2022 by pacemaker1000

[ProDave]

Total bodge.  My opinion, you need a new plumber, one not wearing spurs.

 

You didn't answer the context, has this just been put in in your house or is this a house you bought like this?

 

That gate valve at the manifold needs replacing with an automatic bypass valve.

[pacemaker1000]

This was in house on purchase.

so does it work as I described?

why would I need a gate valve or any valve on the  manifold given the setup!

 

looks like in theory setup is correct just that it’s at the boiler not the manifold to save having to do it twice for second floor.

valves on manifold were a mistake

 

control panel set to room temp of 25 which is about right also max of 40 makes sense for UFH?

Edited September 30, 2022 by pacemaker1000

[billt]

I wouldn't be so quick to condemn it.

 

The black box above the pump is controlling a blending valve, so it might not be as bad as people are assuming. If the system is only UFH with no radiators then it's probably a perfectly acceptable system.

 

These valves usually have a controller to set the temperature so I'd guess that the temperature sensor on the manifold flow does to a controller (presumably the off white box labelled EMR-1) and the controller sets the blending valve to the right temperature.

 

Just because it doesn't look like a modern installation doesn't mean that it's defective.

[JohnMo]

Not sure I agree it's a total bodge. Just an older way of doing things.

 

Here are a copy of the operation instructions

 

 

emr-11.pdf

[pacemaker1000]

Cheers guys especially for the PDF diagram. This is exactly my setup!

I do have two manifolds and both are in concrete so same temperatures.

 

any ideas on settings for 'room temp' and 'limit' 

 

I thought the ideal temp was about 40 degrees so expected to see a dial to select that not room temp set to 25 degrees as that is the desired room temp controlled by individual stats in the rooms?

 

also don’t see point in mixing valve on each manifold when both require the same temp from the boiler?

if the flow is sending 40 degrees to each zone why would you want to cool that down with the return cool water??

 

cheers

[JohnMo]

Previous owner obviously liked a hot house.

 

Room temp, set to what is comfortable to you. Let's say 19-20.

 

Limit, set it low say 30-35 deg, if your room doesn't heat up after a about 6 hours add a little more heat.  You want flow temp (limit), as low as possible to prevent temperature overshooting.  Your flow temp depends on your insulation and general house insulation.  The better the insulation the lower the flow temp.

 

Leave the system as it is, your system does the the same as mixers on each manifold.

[pacemaker1000]

So you saying 30-35 is the flow temp?

any thoughts on the manifold mixers? Why would you use them if the flow temperature is already set correctly?

[JohnMo]

You don't have manifold mixers? Use what you have got.

[pacemaker1000]

1 hour ago, JohnMo said:

You don't have manifold mixers? Use what you have got.

I do have them but turned them off as temperature already controlled by blending valve 

doesn’t make sense to cool down the controlled temperature with cold water 🤷🏼‍♂️

[JohnMo]

The pdf I attached, states that it is a by pass valve, it's not a blending valve.  It's there to give a min flow rate, so if one or more room thermostats have switched of the manifold actuators the pump still has a flow path.  It would have been set during commissioning, so hope you recorded it's position before moving things about.  It needs to be part open.

[pacemaker1000]

Both open just a quarter turn

[Nickfromwales]

On 30/09/2022 at 11:50, pacemaker1000 said:

This was in house on purchase.

so does it work as I described?

why would I need a gate valve or any valve on the  manifold given the setup!

 

looks like in theory setup is correct just that it’s at the boiler not the manifold to save having to do it twice for second floor.

valves on manifold were a mistake

 

control panel set to room temp of 25 which is about right also max of 40 makes sense for UFH?

There are usually 2 blending / pump sets for each floor, so you can select the flow temp per floor ( heat crises etc ). Different emitters in the same house ( slab downstairs and aluminium plates upstairs for eg ) perform very differently so you need that function to set and commission correctly. 

 

What you have is the most basic and tbh crude system available today, which, looking by the age of the installation, is exactly what I would expect to see from an UFH install of ‘yesteryear’.

 

The boiler will cycle up and down and never give the exact same flow temp, and that will become even more coarse / erratic as the zones start to switch of flow and the heat load becomes very low. The hysteresis of the boiler stat is not at all ideal to be used as a master control for managing the injection ( flow into the floor ) temp and I would certainly be upgrading all this if it was in a house I adopted. 

 

If this is your long term residence then I would make some improvements / updates to make the system more refined. For eg, the black manual valve that you’re using for governing the flow temp at source is wholly unreliable as it uses the differential of flow and return. Plus the yo-yo boiler flow temp to dictate its sum output, and that will be less than reliable compared to a thermostatic blending valve like the Reliance one posted earlier ( red control knob ).

 

Two UFH manifolds sharing the output of one primary circulation pump will also suffer from imbalance of demand, as it is dynamic, and will mean certain higher resistance loops ( longer runs ) will become neglected in favour of shorter loops ( path of least resistance ) so not having pumps and blending valves on each manifold incurs a host of problems.

 

I’ve been doing these types of installs for over 25 years now, so have a bit of an idea of what to do to improve things, if that’s what you’d like to do? Failing that, you can buy pipes stats on eBay for the price of a coffee, and stare at them as often as you like