New boiler recommendation

[ianmcd]

I just checked again on Intergas site for their Heat only boilers it states "The Intergas Compact HRE OV open vent boiler is a central heating-only boiler to be used in an open vented system with a header tank."

The heating design is to a pressurised Thermal store with correctly sized expansion vessel on pumped primaries ..... it is not an open vent design.

The Intergas HRE SB is the system boiler that you would use, that is what the abbreviations mean OV open vent, SB system boiler

 

[muggles]

The Thermal store is an integral part of UFH design, it cost a lot of money and it works well - nothing wrong with it so don't need or want to change - also there would be no benefit to doing so.

Apart from making your boiler much more efficient and reducing wear and tear of course, but I suppose if running costs aren't a concern...

The UFH should not be run direct off the boiler .... this is low temp heating, and running boiler at that low a temp would be inefficient.

Hokum, no idea where you've got that from

I would probably find that maintenece contract may be an issue - companies don't like non-mainstream boilers ..... as their engineers are not traioned on them, unfamilair and don't carry spares.

I know you mentioned - don't need a contract - I do as whole central heating needs to be coverred not just boiler, and the gas hob.

Well they wouldn't need to carry spares, and maintenance contracts are generally a waste of money anyway. It's almost always far cheaper to keep the money in the bank and pay a trusted local engineer as and when you need to, although going back to point 1 maybe running costs really aren't a concern for you

I just checked again on Intergas site for their Heat only boilers it states "The Intergas Compact HRE OV open vent boiler is a central heating-only boiler to be used in an open vented system with a header tank."

The heating design is to a pressurised Thermal store with correctly sized expansion vessel on pumped primaries ..... it is not an open vent design.

It can be used on a sealed system with a sealed system kit, or open vented without one. It's essentially the same heat exchanger across the range, albeit the OV one has pipes coming out of the top rather than the bottom

 

[HERTS P&D]

Just like buying a car, buy one made in the UK and keep the jobs in this country.

But you drive a Renault Trafic???

Andy

 

[sxturbo]

The Thermal store is an integral part of UFH design, it cost a lot of money and it works well - nothing wrong with it so don't need or want to change - also there would be no benefit to doing so. The UFH should not be run direct off the boiler .... this is low temp heating, and running boiler at that low a temp would be inefficient.
Far better to have long full efficient burn and store the heat .... then use that at low temp as required.

It wasn't just SSE not heard of Intergas, just had an indepeneadnt Heat engineer at a propery I rent out, he had never come across Intergas.
I don't dubt technology of Intergas may be good .... but they are not widespread, and when I checked no local suppliers (nearest is in Newtown) and nearest approved installer is 150 mile round trip ...... so unfortunatley they do not have enough coverage.
I would probably find that maintenece contract may be an issue - companies don't like non-mainstream boilers ..... as their engineers are not traioned on them, unfamilair and don't carry spares.

I know you mentioned - don't need a contract - I do as whole central heating needs to be coverred not just boiler, and the gas hob.

A pity as having looked at the webiste the technology of some parts is good.

Modern boilers like to run at low modulation / low temp this is what they are designed for and is within there efficiency, my intergas for example has operntherm and regularly limits the flow temp to 35 degrees and the boiler has been set to never go above 65 (this can be set lower if required) when on heating mode so it stays in its efficiency condensing phase.,this should be possible regardless of what boiler you get, don't get hung up on someone saying intergas, all boilers these days are pretty much the same in terms of quality if they weren't they wouldn't have very lengthy warranties.

I would get rid of the seperate pump and fit a system boiler.

however the best advice is to choose a decent installer an go with what they recommend, its far harder to find a decent installer than it is a bad boiler. A decent installer will be able to set the new boiler exactly right for efficiency etc, a bad installer will just sling the boiler on the wall take your money and leave, without doing anything with the settings to maximise the efficiency.

 

[MeldrewsMate]

But you drive a Renault Trafic???

Andy

No I don't; if you're going to stalk my posts then please read them thoroughly. At no point did I say it was my van...Still, as they say in politics, if you can't discredit the argument, discredit the speaker.

 

[HERTS P&D]

No I don't; if you're going to stalk my posts then please read them thoroughly. At no point did I say it was my van...Still, as they say in politics, if you can't discredit the argument, discredit the speaker.

Not stalking, but just pointing out that your French van (that you were driving) broke down abroad.

Did you say in the post 'it wasn't your van'??

Andy

 

[MeldrewsMate]

Not stalking, but just pointing out that your French van (that you were driving) broke down abroad.

And I definitely wasn't driving it!

Let's put this spat to bed. You were having a pop at me because I support Britain and jobs in Britain. It's one I hear a lot, usually from people who have never thought about where jobs come from, and how not buying the things we make here will make us all poorer eventually. They gleefully point out that the rubber in my tyres doesn't come from Britain, and the list goes on; but the fact remains and is yet to be proved wrong that every pound that leaves these shores makes us all a bit poorer. The bloke who gets rich by importing stuff that could be made here is getting rich at the expense of many other people's income, and we all pay for that through the social care/dole/tax system. Just because I'm not perfect (but quite close) doesn't change that argument.
Suggest a new thread if you want to discuss further; I think this one was originally about boilers

 

[HERTS P&D]

Ok, the van that you were travelling in................................and trying to fix!!

Andy

 

[muggles]

...but the fact remains and is yet to be proved wrong that every pound that leaves these shores makes us all a bit poorer. The bloke who gets rich by importing stuff that could be made here is getting rich at the expense of many other people's income, and we all pay for that through the social care/dole/tax system. Just because I'm not perfect (but quite close) doesn't change that argument.
Suggest a new thread if you want to discuss further; I think this one was originally about boilers

Maybe so, but on the subject of boilers the list of wholly UK-based and UK-owned gas boiler manufacturers is vanishingly small. In fact, I can only think of one

 

[MeldrewsMate]

Maybe so, but on the subject of boilers the list of wholly UK-based and UK-owned gas boiler manufacturers is vanishingly small. In fact, I can only think of one

...and that's because WE, the specifiers are chosing to specify/buy foreign boilers rather than domestic (please, can we have this argument in a new thread), and neither are we complaining enough to the British based manufacturers that they are sourcing their boiler parts from Abroadland. It comes across that we, as a nation, don't seem to care whether our products are made in the UK or in Abroadland.

An example? The Grundfos UPS2 pump: Was made in the UK, about a year ago boxes started sporting the 'made in Serbia' badge. Did anyone notice? 50 jobs lost in Sunderland. Fifty families with less to spend on meals out, cinema tickets, footie, accountants, new cars, etc. 50 more drawing money from the exchequer rather than paying into it. That's how it makes us all poorer.

It is also very rare to hear of a pro-active 'complaint' ie "We hear that you're considering contracting out your foundry operations [to an offshore enterprise], thus making x redundant in this country. Please be aware that we will be as loyal to your boilers/products as you are to our country".
Companies have egos too, and once that chief exec states that he's moving production abroad it takes more that a little effort to persuade him to change his mind - much better to warn him of the potential loss of sales before that choice is made.

 

[RickH]

Some have said install a system boiler, ..... my concern is that there is an existing pump & expansion cylinder. OK they could be removed .... but there are a number of control questions, and I have a concern boiler installer would understand or be able to modify the control board.

It sends heat signal to boiler ( based on thermal store temp)
It controls anti-heat siphon 2 port vale on primaries, and also use open/closed signal in Control board logics. It also runs demand based on 12 temperature zone controllers. (digital stat & 7 day programmers with set temp back )

The control board for example detects flow when HW is drawn off ( its main pressure through store heat exchanger )opens anti-syphon valve, and once open runs primaries pump without starting boiler ... this provides stir of the thermal store to keep hot water flowing over heat exchanger.
Getting system boiler to do that would seem to introduce complexity. (And may not be possible without voiding warranty)

It all works well, so see no need to make change and risk screwing it up.


So it seems my option may be to swap out with Vailiant EcoTech Plus. In 30KW size

Annoying you have to use their approved installers to get full warranty ...

 

[sxturbo]

Your current setup just sends a 240v power signal to the boiler, it doesn't do anything fancy, it is a series of micro switches that tells the boiler to switch on or off.

Swapping to a system boiler will be no problem, the controls act exactly as they do now, except the pump will be removed as it's built into the boiler, nothing else needs to change.

If you go for an intergas for example you get full warranty and it can be set up in any configuration you want, albeit with its built in pump. The eco RF doesn't have an expansion tank built in so the existing one will remain.

 

[RickH]

I won’t not go for Intergas .....asked several gas installers recently, none of them ever come across one. Only 1 of them had even heard of Intergas.
The nearest installer is 100 Mile round trip .... too thin on the ground for me.

On the system boiler ... it controls the pump, how could the control board controlling pump for Thermal store stir, work that pump without mains connection to it ? Just seems to introduce design change that Underfloor Heating Company won’t be able to support & boiler manufacture won’t be interested in ....

I just can’t see it working ..... and it would not seem to add anything ...
Boiler efficiency would be the same if I use non-system .... (from Vailliant site)

 

[muggles]

The system boiler controls the pump which heats the thermal store, just as your current heat only boiler does. The pump which runs to your heating is controlled by your heating.

You seem very determined to not see the best ways of doing this. You don't need to understand how it works anyway, that's for your installer. As for efficiency, you're not going to get anything like the efficiency quoted on the manufacturers' websites if you keep the thermal store - it runs too hot for condensing boilers, so realistically you'll get around 80% efficiency

 

[RickH]

I only asked for advice on the replacement boiler, was not looking to redesign & replace huge parts of the system. Though happy to listen on boiler options.

To be clear though to save repeat suggestions - I absolutely need to keep the thermal store ..... it is an integral part of the Underfloor Heating System (there are no radiators) the system designers & suppliers warranty their system & design, and it states explicitly that the UFH must never be run directly off a boiler ..... it is run off the stratified lower section of thermal store and its dedicated heat exchanger. Water temp is set to 60degree in the lower stratified zone.

I had assumed just swapping the Baxi out to another 'heat only Boiler', am happy to consider a system boiler if it can show any benefits, and importantly will work with existing control & input requirements, without modifying circuit boards on system.


The concern is the 'stir' function and how that could be achieved if pump control is moved into the boiler.

At the moment the boiler is nice an simple ...... heating zones work downstream of store, own pump etc. When they have exhausted heat from the store, store thermostat signals this to control board .... it operates relay and opens anti-syphon valve, when it is fully open it signals back to control board, it starts relay for primaries pump, then operates boiler relay and sends 220V to the boiler. (these relays are on-board on the system control board)
Boiler then runs/modulates as necessary until the store up to temp - at which point control board then drops 220V to boiler operates an overrun period then shuts down pump and anti-syphon valve.

In use on DHW once flow detected - after 30sec delay (in case of small water draw off) anti-syphon valve opens, signals to control board when fully open and it starts primaries pump but no 220V to boiler, this provides stir to Thermal store.

I accept none of this is rocket science – but it works, and works very well.