Atmos or Intergas

[Brightonguy]

I see. To stop boiler cycling.

I looked at Youtube and saw some vids on the Atmos/Intergas. The man boasted that the combi had a standard off the shelf pump that only does the CH and not the hot water as it is not needed for hot water. A great advantage of course as these are cheap and any make can do the job. It has just stuck me that if this was replaced by a Grundfos Alpha, or Wilo equivalent, and flow switch on the heating flow pipe and have rad valves on all rads, even the bathroom rad, then there is no need for room two stats. Would Atmos/Intergas go along with this? Also the pump, would modulate down if only one zone is on and not running too fast.

Dan, do you care to comment?

 

[Agile]

You are not understanding the need for a room stat.

If all the room stats close then your boiler would be left running to keep itself hot. This wastes your gas!

The Intergas uses a Wilo pump but this is inside the boiler can cannot be changed for another make.

Tony

 

[Brightonguy]

Agile, I do understand the need for a room stat, to stop the boiler cycling when there is no heat demand. I noticed on the Intergas from the youtube video that the CH only pump maybe can be replaced by a modulating pump and flow switch to cut out the boiler when all the radiators thermo valves have shut down. There is lots of space in the boiler to change the pump. That is why I asked Dan to comment as he deals with these boilers. If the pump can be exchanged for a modulating pump then this is the answer to getting rid of wall stats.

 

[Dan Robinson]

I see. To stop boiler cycling.

I looked at Youtube and saw some vids on the Atmos/Intergas. The man boasted that the combi had a standard off the shelf pump that only does the CH and not the hot water as it is not needed for hot water. A great advantage of course as these are cheap and any make can do the job. It has just stuck me that if this was replaced by a Grundfos Alpha, or Wilo equivalent, and flow switch on the heating flow pipe and have rad valves on all rads, even the bathroom rad, then there is no need for room two stats. Would Atmos/Intergas go along with this? Also the pump, would modulate down if only one zone is on and not running too fast.

Dan, do you care to comment?

You are mis reading so many things. If you use a flow switch to stop the pump the boiler is still going to cycle. Also - how will it know to spin the pump again when the trv's open?

As Tony said - the integral pump of the intergas can not be replaced. Although the one in the Atmos version could with approval from Atmos in writing. However, with the pump on minimum and the boiler will spend even more time cycling that necessary.

I think I know the person you are referring to on You Tube and he would be talking about the Atmos version rather than the Intergas. He is also recall a couple of his videos being inaccurate; as well as not necessarily "in date". The Atmos boiler had a couple of hardware revisions, although the pump was easy enough to replace with another boilers pump - but it wasn't possible to fit a standard 1.5" union pump such as the Alpha (or Wilo equivalent).

I really think you are over thinking the application - certainly beyond your practical knowledge/abilities.

 

[Brightonguy]

Dan, no, that is not what I am on about. The flow switch is wired like a room stat and switches in and out the burner only, leaving the pump running. Not switching in the out the pump. Is that what a stat does on an Intergas, just switches out the burner and leave the pump running?

I don't think I am over thinking here, as most boilers I have come across the stat only switches out the burner and the pump keeps running. All I am thinking of doing is replacing the standard Wilo with a Wilo Smart and replace the room stat with a flow switch. That is easy to do and far easier than running a wall stat cable. The flow switches have a minimum flow in which they switch out the burner. A friend had a Baxi boiler with a built in flow switch on the heating pipe that meant rad vales can be on all rads. The boiler was crap though and was always breaking down being a Baxi, but the idea was nice.

OK use a Wilo modulating pump for the Wilo in the supplied combi and not another make. You wrote with writing the makers will go along with this arrangement. Are you saying that the Intergas pump is not a standard thread and the Atmos is?

 

[Dan Robinson]

You can't do it.

The boiler uses complicated algorithms and resistance readings from two temperature sensors to control what the burner does and when. There is no way of overriding this circuit.

Don't think you can just splice the wiring so that the switch cuts out the sensors. The boiler will lockout. I can think of a way of doing it but it is stupidly complicated when all you want to do is control two zones. If running cables worries you, then use wireless controls. Honeywell RF2 pack 5 fro example is a dual zone wireless controller with 2 wireless stats talking back to a central controller by the boiler/zone valves.

I also know what Baxi you are referring to and the flow switch was more to do with safety than efficiency.

Smart pumps have bigger electrical housings and will not fit inside the Intergas. Atmos MAY allow a different pump to be fitted, but not by just anybody. Unless you get it in writing from the manufacturer it is illegal to modify the appliance. The thread is a standard one, but not a STANDARD one. They are OEM pumps - just like Alpine make the Audio units for Honda's as well as their own stereos.


Trust me. I do this for a living, and the professionals here will confirm I can come up with all sorts of bizarre complicated control arrangements when the mood takes me. You are over thinking a problem that isn't there. You will make life easier, cheaper and more efficient if you zone the house using Pack 5.

 

[Brightonguy]

Dan, I want rad valves on all rads ideally. That precludes a wall stat(s). I am lost on what you are describing. Does the Intergas pump run at just the same speed or is it modulated by the boiler? If it runs at the speed the installer sets it (I assume the normal three speed), I fail to see that the other controls have a baring on the pump. They would only come into play if they modulate the pump (besides switching it in and out of course).

So, the Intergas pump, does not have the standard threads?

I know the makers would need to be contacted before there is any replacing of the pump.

The Youtube vids on the Intergas make it look like a well made and well thought out piece of boiler. Looking at the vids it looks like the whole lot can run with the pump not running. Indeed it does under DHW on the combi, which make me think it is ideal for have a Wilo Smart pump. IF that isn te case they should be offering A Smart pump as an option complete with an integral flow switch. Maybe I should be in their marketing dept.

The Baxi with the flow switch did enable all rads to have rad valves though. Neat idea and others makers should do the same. The trouble he had with the boiler put me off it. It was just badly made parts which were badly put together.

 

[Dan Robinson]

I am talking about burner modulation not pump modulation. If you are lost, it is because you are not wanting to listen to reason. Please forget about the Baxi - it is a different technology altogether.

I also fail to see why you won't take on board what we are telling you.

They also have a new version in the pipeline with various new features, btu the UK release date is not known.

The pump speed on the internal pump is set depending on heat load required.

If you insist on throwing the regulations out of the window and having smart pumps on combi boilers then look at getting a low loss header or running the boiler's heating circuit through a plate heat exchanger.

Why are you insisting on putting trvs on ALL rads? It makes no sense whatsoever.

 

[ecowarrior]

I think Dan has understandably withdrawn from the Arena!

Nope bless him - he's still trying

 

[ecowarrior]

lets think : You tube vid - vs - very experienced ATMOS / Igas agent, installer & general all round heating guru - - -

 

[Dan Robinson]

What the OP doesn't know - is that I already know how to do what he wants, and even have the wiring diagram drawn (well - one would just need to add the flow switch) .

Why?


I needed to control my own boiler are certain way for an experiment that could easily be modified to suit the OP's needs.

However....

Bye Bye warranty.

Bye bye building regs.

Bye bye the chances of finding an installer to do the work.

Hello, illegal installation.


OP - I have been fitting these boilers in various elaborate setups since 2004. What you are trying to achieve is pointlessly complicated and non compliant.

 

[Brightonguy]

Dan, thanks for your input. I see you are a thinker and amending your controls. We think alike

I downloaded the instructions:

4.2 Central heating mode When a heating demand is requested (power is on, the timer and thermostat are calling for heat) the integral pump is energised and the boiler will fire automatically. The hot water is now circulated around the central heating system. When the end of the central heating demand is reached (the thermostat reaches temperature or the time clock reaches the end of its set period) the burner will shut down while the pump remains functioning during a preset period of time to dissipate any excess heat from within the boiler’s heat-exchanger. After that the boiler will revert to stand-by, waiting to respond to the next heating or hot water demand. During the heating period a call for hot water will take preference over heating.


The pump does not modulate, even though the burner obviously does. The pump is an ordinary 3 speed pump as the vid says (but maybe not the threads). When the stat is satisfied the burner is switched out and the pump overruns and then is switched out. So the pump is not running all the time when the clock switches on CH heat like many other boilers

But like you I think a bit. The wire for the integral pump could be disconnected. An external Smart pump could be fitted on the CH flow with a flow switch and switched on by the CH time clock and Bobs your uncle. Or if the integral pump is a standard thread fit the Smart pump fitted in its place. Or the Smart Wilo head screwed to the existing body? The makes would not like it, and disown it, but it would work.

It is not daft wanting temperature control in every room - having rad valves on all rads.

 

[Dan Robinson]

The smart pump head won't fit inside the boiler.

Having TRV's in each room is fine bar the one that you are REQUIRED to house the room thermostat.

You are sadly falling foul of a poorly translated manual (assuming you have pasted that text from the manual).

When timer and room thermostat call for heat the pump runs. The burner will activate and modulate the flame to match the temperature to whatever the set point is.

If the heat load of the property is below the minimum output of the burner (5.6kW for the 24/18, then the burner will eventually be shut off as the flow temperature (calculated from the difference in temp sensor readings) goes higher than programmed setpoint.

NOTE: The sensors are not measuring the water temperature like the thermostat on the Baxi.


When the programmed setpoint of the boiler is reached the burner shuts off and the pump continues to run.

The pump will continue to run until the time clock or room thermostat are satisfied.

Leaving a disconnected pump in the boiler will hobble the amount of water than can flow through it.

Why you would purposely invalidate a warranty to not gain anything in efficiency is beyond me, but it seems you know best.

Again, you are modifying the appliance and it is deemed an illegal installation.


I perhaps should also point out that I have individual room control of my house using wireless thermostats in each room.

There is little you can think of that I haven't tried .

 

[doitall]

If you want TRVs on all the rads why not go the whole hog and look at the Honeywell EVO home, with HR 80 programmable radiator valves.

 

[Dan Robinson]

Like what I used to have