Help needed replacing lockshied with TRV body

air

Hi,
I want to fit some Honeywell Rondostat TRVs to my rads and picked up a Myson (rebranded by heatmerchants) TRV today to use the valve body from it.
Now the Rondostat fits the valve perfectly and the throw of the actuators match spot on.
The issue I'm having is fitting the TRV body to the rad.

The pipe exiting the rad (marked in red in the attached pic) is smooth and not threaded. Ideally I would like to unscrew it at that point and screw in the fitting that came with the TRV valve body.
Is it possible that this pipe is not threaded and is part of the rad somehow?

I've tried and failed to unscrew it, access is difficult due to the limited length of pipe between the rad and the large nut.

I have the lockshield removed at this point obviously.

Thanks in advance for any help.

sullzz

air wrote: »

Hi,
I want to fit some Honeywell Rondostat TRVs to my rads and picked up a Myson (rebranded by heatmerchants) TRV today to use the valve body from it.
Now the Rondostat fits the valve perfectly and the throw of the actuators match spot on.
The issue I'm having is fitting the TRV body to the rad.

The pipe exiting the rad (marked in red in the attached pic) is smooth and not threaded. Ideally I would like to unscrew it at that point and screw in the fitting that came with the TRV body.
Is it possible that this pipe is not threaded and is part of the rad somehow?

I've tried and failed to unscrew it, access is difficult due to the limited length of pipe between the rad and the large nut.

I have the lockshield removed at this point obviously.

Thanks in advance for any help.

It is threaded , the way to remove it is , you disconnect the valve body from it and use a rad spanner , its basically a large allen key which fits inside it , some type dont take as they are a different shape internally , but you can buy a universal type one in any plumbing shop possibly even b & q or the likes

air

Thanks a mill sullzz, you were spot on, it never occurred to me to look into it and obviously I've never replaced one before!
The fitting that came with the new valve body has a section to get a spanner on it so that threw me also.
Thanks again.

aujopimur

Disconnect the pipe from the valve,make sure the flange nut is tight on the old valve, you should be able to unscrew it by turning the complete valve body.
If you're in the Cork area I can loan you a key.
Relace the wheelhead instead of the locksield, or put the l/s cap on the other valve for balancing.

air

Thanks aujopimur, I got a key in HM for 7 euro when I was back ordering the other valves.
This was the wheelhead end sorry, there's a capped lockshield on the other end also.
The Rondostat is installed and working now, great piece of kit.

In case anyone ever needs to install one, 2TRV 15AN (vertical head) and 2TRV 15IN (horizontal head) are 1/2in valve bodies from Myson that work with the Honeywell heads.

JohnnieK

air wrote: »

Thanks aujopimur, I got a key in HM for 7 euro when I was back ordering the other valves.
This was the wheelhead end sorry, there's a capped lockshield on the other end also.
The Rondostat is installed and working now, great piece of kit.

In case anyone ever needs to install one, 2TRV 15AN (vertical head) and 2TRV 15IN (horizontal head) are 1/2in valve bodies from Myson that work with the Honeywell heads.

Can I ask why you chose the honeywell head over the one that came with the valve? Just curious.

air

No probs Johnny, the Honeywell unit is far more sophisticated than a standard TRV.
In manual mode it works like a normal TRV with a digital set point to 0.5 degrees C of precision. In auto mode you can program it differently for 7 days of the week (or all days the same) with two on and two off times with set temperatures for each.
So for example you can set a bedroom to be warmer in the evening and a bit cooler going to bed at night.

It's very nearly as good as having a zone for each rad. Each unit takes two AA batteries but they last 2 years and Sanyo Eneloop low self discharge rechargeables are ideal.

heinbloed

Now don't forget to rebalance the system.

air

I wouldn't have thought balancing would be that important with TRVs on all rads?
Unless the boiler is undersized the system should even itself out.
The Honeywell TRVs use PID control to give very good temperature control.

JohnnieK

It should still be balanced. The boiler is not self regulating in that sense. The pump will still favour the path of least resistance.

air

But surely the TRVs will open and close with room temperature sending more flow to rads with the valve open widest.
Surely balancing is only relevant where you have a rad that is not getting up to temp quick enough or at all. I've never had that issue even with all rads fully opened as my boiler is obviously more than sufficient for the number of rads it supplies. With TRVs installed I think it is even less of an issue.

heinbloed

Checkk the www. why it makes sense to adjust the hydraulics, why balancing the system saves on money and increases comfort. Or look at the previous posts concerning this issue.

Whenever there was a change made to the hydraulics a rebalancing must be made as well.

It doesn't matter why or where this change in the hydraulic system was made - a balancing is always necessary to optimise the system.

air

I did a bit of reading up on it and my findings support what I've said above - if all the radiators are heating up properly then there is no need to balance anything.

Two quotes from the first thread I found on the subject support this - from http://forums.digitalspy.co.uk/showthread.php?t=1127472:

May I establish something, are you happy with the heat output from all your rads? if so your system does not require balancing.

The above is a general rule of thumb, not an absolute, in a small property it might not make the blindest bit of difference if all the valves are opened or shut most of the way.

I live in a small property, all my rads heat up fine and the TRVs when all fitted will control the temp in each room and restrict the flow on rads nearest the pump automatically - in fact in a far better way than any static hydraulic balancing could ever achieve.

Can you give me a good reason why my system needs balancing?

heinbloed

Can you give me a good reason why my system needs balancing?

Yes. But if fuel efficiency, safing on money, repairs, maintenance and the environment as well as increasing comfort are no good to you - then not.

Please: if you quote someone or something - name the source.

The first quote seems to be a question without a question mark

Quote:
May I establish something, are you happy with the heat output from all your rads? if so your system does not require balancing.

(lack of literacy skills, propaganda, out of context - we don't know what in what relation this was written. Or where, or when ....)

Quote:
The above is a general rule of thumb, not an absolute, in a small property it might not make the blindest bit of difference if all the valves are opened or shut most of the way.

We simply don't know to what this sentence refers to, quote correctly please. It makes things easier.

air

I've added the link to my post.
Can you explain to me how exactly how balancing will save me on money, repairs, maintenance and the environment?

heinbloed

Can you explain to me how exactly how balancing will save me on money, repairs, maintenance and the environment?

Yes.

There are plenty of sources in the www.. which one have you found so far?

Money:

The maintenance costs are reduced, the flow temperature reduced, the return temperature reduced. Less fuel is burned for the same level of comfort. Less energy is lost during transport via the pipes and at the boiler. Less electricity is used for the pump.

Repairs:

Lower system temperatures cause less stress on all parts involved. Fewer re-adjustments, lesser calcification, less rust. The pump's lifetime is increased by allowing it to work at the correct speed.

Maintenance:

A combination of the above.

Comfort:

Less sudden changes in temperature and no noises from the circulating water, expanding and contracting apliances.

There are propably more reasons, check the www.. If you find a good site explaining the issue in simple words link it here in the forum.

air

I have already posted the link to my quotes above in my earlier post, you may not have spotted my edit.

I understand the benefits of balancing on a system with manual flows.
However I'm not convinced of it's benefit on a system with TRVs fitted where the boiler is adequate for the number of radiators supplied.

As I understand it the aim of balancing is to reduce the flow rate through radiators nearest the pump by closing down the lockshield on the return side of the radiator. If done properly this ensures that the flow rates through all the rads are equal.Thies ensures that enough flow gets to the furthest away rad such that it's power output is not reduced. This also ensures there is sufficient temp drop across the nearest rad to ensure a low enough return temp to ensure efficient boiler operation.

However, I don't accept that this applies when using TRVs.
Assume the simplest system - a boiler with two rads 1 and 2. Rad 1 is close to the boiler, rad 2 is 20m away.
With no balancing and manual valves on both rads the following would occur.
Rad 1 will have a higher flow rate as there is less pressure drop across it's shorter pipe run.
Rad 2's flow rate will be reduced and so it's maximum power output will be reduced.
The excessive flow rate through rad1 and it's proximity to the boiler will mean that return temps are elevated vs if the system was balanced.

Now as I understand it the above is the rationale for balancing and it makes sense to me.

Now consider scenario 2.
Rad1 and rad2 positioned as before, no balancing - lockshields fully open, but with TRVs installed.
Boiler starts with house cold.
TRVs on both rads will be fully open calling for full flow.
Rad1 will again get more flow, and so will heat up quickest. However as soon as the room is up to temp, the TRV will close and increase the flow to rad2 which will then come up to temp.

So, it seems that with TRVs installed balancing only has an advantage on startup performance.

However balancing also has a disadvantage in that it limits the max flow to rad1 less than it needs to be.

Consider that the house has warmed up but then the room rad1 is in gets cold - door left open or whatever.
The TRV immediately opens fully.
If the sytem has been balanced, the flow to rad 1 is reduced by the partially closed lockshield and so the room takes longer than it otherwise would to get up to temperature. This disadvantage would apply also to any rads between rad 1 & 2.

In my case my boiler is having no difficulty supplying all my rads with full power and in light of the above I don't see any advantage in spending time balancing flows.

If you can explain the risks you quote above i'd be interested in hearing the rationale behind them.

The only disadvantage I can possibly see is temporarily elevated return temperatures when the house is cold and rads nearest the boiler are calling for full heat. At all other times it will actually increase the potential power output of each of the individual rads by allowing full flow through them when required.

My system is probably balanced somewhat anyway given it's even room performance and as such I don't see the need to tinker with the balancing purely as a result of fitting TRVs.

heinbloed

You propably haven't found any serious web source explaining the situation sufficiently.

It doesn't matter what type of valves are involved. As long as the system (and this consists of more than radiators) isn't balanced the building regulations aren't met.

Meassure the temperature at the outlets of your radiators. And post the results here.

The SEAI has a page about the issue as well, very plain. This might be ideal for you to get a glimpse at the basic balancing methods.

The circulation pump manufacturers - who do not consider CH systems are installed without TRVs - have all the info's you need.


The laws of physics and economics aren't beaten by the installation or non-installation of parts. Follow logic.

heinbloed

BTW:

The TRVs should be ideally placed at the top of the radiator. Not at the bottom.

air

Well obviously you can't explain where I'm wrong in my thinking anyway as you keep directing me to the web rather than engaging in a discussion.

What do you mean about TRVs being installed at the top of a radiator? The pipes are at the bottom of the rads obviously. Is it the flow or the return end you are referring to?
Surely the TRVs should go on the same end as where the manual adjustment valves were as they are doing the same job.

heinbloed

@air:
There is nothing to be discussed.
The laws of physics are universal, no matter if you wish to discuss them. Your questions are irrelavant to thermodynamics. This is a technical forum, religious and supernatural issues can be

discussed

in a different forum.

Open a new thread: "discussing thermodynamics"

Or pay a heating engineer to have a look at your system, he/she will charge you by the hour for discussions.

A chance for enlightment you might find here:

http://www.grundfos.com/service-support/encyclopedia-search/balancing-valve.html

http://www.grundfos.com/service-support/encyclopedia-search/balancing.html

and as an overview

http://www.grundfos.com/service-support/encyclopedia-search.html?l=B

In the developed world the hydraulic adjustment is done per calculation - a legal requirement in most nations b.t.w. - using tools like this:

http://waerme.danfoss.com/Content/817e514f-e85a-4577-b906-38ec9cb2ff9a.html

What do you mean about TRVs being installed at the top of a radiator?

Read the manual.

air

I never denied the requirement for balancing, I think I showed an understanding for why it is required in my above posts, especially for systems with manual radiator valves.

I have found your posts in this thread very unhelpful.
I posted about a problem I was having and was kindly helped by Sullzz.

You subsequently brought back up the thread with a one line post saying I needed to balance my system.

You haven't provided any reasoning or logic as to why I might need to balance my system due to installing a TRV alone.

All you have done is point with vague notions to the www regarding issues which you haven't detailed.
As for your "read the manual" comment, pure ignorance on your part.

As for the laws of physics I would hazard a guess that I am a lot more qualified in the area than yourself.

gifted

heinbloed wrote: »

BTW:

The TRVs should be ideally placed at the top of the radiator. Not at the bottom.

Excuse me for asking but if a TRV is fitted at the top of a rad then would it it get a false reading from the heat that rises up from the rad? Always thought that they picked up the temp from low level

air

I think he was talking about the flow vs return end of the rads as obviously a TRV is fitted at the base of the rad where the pipes enter - unless there are models with remote temp sensors or something. I asked him to clarify earlier but he just gave a smart answer as seems to be the trend.

heinbloed

Gifted asks:

Excuse me for asking but if a TRV is fitted at the top of a rad then would it it get a false reading from the heat that rises up from the rad? Always thought that they picked up the temp from low level

Read the manual as well, gifted.

The TRV makes little sense at the coldest spot in the room ( at an outside wall at the bottom of the radiator), as chosen by air. They should be placed at around 1m height. The positioning chosen by air couldn't have been worse.

The modern Honeywell TRVs ( as used by air) have a "window-open" function, this would not work with a positioning at the bottom of the radiator.

air

How do you know where my TRV is positioned? As it happens the one installed on the valve shown in the picture is not on an external wall.
How pray tell do you suggest installing a TRV at 1m height when the pipes come up out of the ground and go into the bottom of the rad?
With regard being at the coldest point of the room, it's all relative anyway, the setpoint could be adjusted to compensate.

JohnnieK

Your wasting your time and energy air:D

gifted

just checked HERZ TRV on the web and it showed the TRV's on the bottom of the rads

Just reading their website and they have been around since 1896, long time, might mail them Heinbloed and tell them that they too should read the manual

heinbloed

@gifted:

The laws of physics aren't always compatible with the greed to sell.
Bad advise to the picture-influenced public who can't do math nor investigate in documents written by independant researchers is a very good marketing technique....

Clergy men sold pictures doing miracles, a long time before 1896, they made a living from that. And still do so.

Some science teacher haven't done their job properly, could this be ? Propably

been around since 1896

and living in a beehive hut - with central heating. Developed the TRV there, tried and tested, picture included ....

Honestly, gifted: do you believe in pictures, in advertising material? Welcome to this forum.

gifted

Thank you Heinbloed, your rant just confirmed my suspicions...;)

air

Heinbloed I'm inclined to agree with JohnnieK I think, however I'll ask one more time.
A TRV head is fitted to a radiator valve.
A radiator valve sits between the radiator inlet and the central heating pipe.
Radiator inlets are generally at the bottom of radiators.
Please explain how a TRV can be installed anywhere but the bottom of the radiator without extending the CH pipe in a ridiculous loop up to a remote TRV position?

heinbloed

@ air:
After telling us what you think about my opinions you seem to be very desperate still getting them....

air wrote:

As for the laws of physics I would hazard a guess that I am a lot more qualified in the area than yourself.

and

Well obviously you can't explain where I'm wrong in my thinking anyway

Are you not capeable to pay a professional?

No insult here, but the heating system you have so far described and the intelligencia sitting behind it is total crap.
You can by expensive tires for a wrecked car, sure, and then put them into the boot. As the tire manufacturer recommends: store them dry, away from sun light.
A very usefull manufacturer's recommendation. Some follow these rules.

Radiator inlets are generally at the bottom of radiators.

This is not correct.
Only those who want to sell their ill constructions for maximised profits install radiators like that. An extension of the CH pipe

in a ridiculous loop

is the only method to install a TRV in a beneficial method with such an ill pre-condition.

But why installing a TRV anyhow if this seems to be to problematic for a DIYer with limited capeability?
There are other methods to controll a room's temperature, automatical and economical.....

Contact a prefessional and don't troll around. There is help out there, check the yellow pages.


Air wrote:

I have found your posts in this thread very unhelpful.
I posted about a problem I was having and was kindly helped by Sullzz.

You need certainly professional help.

air

The above post shows slgns of language and / or intellectual difficulties and I'm not going to waste any more time trying to communicate with you.
Your posts have added nothing to this thread which was finished when you arrived.
Mods please lock this thread and / or delete all posts after post 7.

sullzz

@heinbloed , the op posted a problem and was looking for a simple solution , i dont know why you felt the need to come onto the thread and start to stir up a load of crap , this is a forum for unprofessionals looking for solutions to their problems , not for someone like yourself to come onto and try to be a hero , are you even a qualified plumber or engineer ?

KoolKid

@Heinbloed. Here we are again. Another thread being thrown in all directions. This forum is about people helping each other. Every post does not need to be literally disected. If you don't wish to help people thats your choice, but there are plenty of professionals here who are helpful. They deserve to be let help people without distractions and off topic petty arguments.
@ Air I can understand your frustrations but please refrain from back seat modding. If you have an issue with a post, keep if off thread & use the report button.
This is only an onthread warning . Back on topic please.