New boiler on old single pipe system

[simond]

We've fitted a fair few Vaillants on 1 pipe systems with no issues.

The Intergas range is a pet subject on this forum. Just like the Keston was, years ago, and then the Remeha Avanta (now called a Baxi Potterton).

Many reading this - who are not boiler installers - will place a high degree of their confidence on a large responsive service backup team available nearly seven days a week.

Unfortunately, Intergas have not yet achieved the market penetration to make offering this financially possible.

They also, as far as I know, do not use British assembly or parts in their boilers......which both Vaillant and Bosch do.

And finally, the Wilo pumps used in Intergas are renowned for premature failure in the UK, a fact that Vaillant ignored to everyones cost in their earlier versions of ecoTEC.

Both Vaillant and Bosch now use exclusively Grundfos, the cheaper badged Vaillant Group sub brands(eg: Glowworm) still get the Wilo offering last time I looked.

 

[Dan Robinson]

Tony - I suggest you read the Greenstar engineer's manual.

Also the Intergas looks at the HEX top and bottom sensors rather than Flow and Return (as you know). Too wide a delta and they will shut down.

Range rating and pump size is vital to prevent nuisance dropping to status 1.

 

[Agile]

You are missing the point of that industrial system, Rick.

Because the flow/return pipe is a 3" diameter it has a very low flow resistance and the usual way they are used is as I described with a flow of 82 C and a return of not much less of about 77 C.

So all rads are supplied with virtually the same temperature.

The domestic one pipe is a very budget system, often with just a single series connection where the first rad will get 82 C but the last less than 70 C often much less.

Of course there are very many variations on one pipe domestic systems but virtually all have a much reduced last rad temp. Those are good for condensing boilers but not very good at providing heating. Particularly as being a budget system the rads are usually undersized as well.

Tony

 

[RickMoore]

Ah yes, I see what you mean now tony, thanks Makes sense now.

 

[Agile]

Tony - I suggest you read the Greenstar engineer's manual.

Also the Intergas looks at the HEX top and bottom sensors rather than Flow and Return (as you know). Too wide a delta and they will shut down.

Range rating and pump size is vital to prevent nuisance dropping to status 1.

When you mention "Engineer's Manual" do you mean something more comprehensive than the standard MI which comes with the boiler?

If so where do I get them?

Most of the MIs for nasty boilers just say something like "Its not necessary to range rate this boiler because it automatically adjusts as required" !

Can you really set the DHW flow temp on ALL of the Worcester boilers?

Are there many more IG setting available than those set out in their MI book?

Like the wide diff drop out for example?

 

[Dan Robinson]

There are all sorts of settings for the Intergas, but you need the software and password to access them.

There is a WB Engineers manual, several versions of which are in out CC repositories, with a myriad of settings - far more than you would ever need.

It has been discussed several times in the CC.

 

[doitall]

The large pipe was probably the entire heating system at on time with the rads being added later.

It would have been a gravity system most likely coal fired.

Keep the system as is the boiler will work just fine, although I would look at Intergas as they are less touchy than some of the Valiant, WB etc.

 

[doitall]

The rad flow rate is primarily dependent on pump pressure. That is largely independent of the temp.

The viscosity of water does appear to reduce slightly as temperature rises but I don't think that will be significant.

Tony

Nothing to do with the pump Tony, The circulation through the rads is by gravity alone. the one that doesn't work just needs taking off and flushing out with a hose pipe and a new air vent.

 

[Agile]

Yes, I should have said heating circuit circulation.

Since a Village Hall is normally a low building on a single floor a gravity circulation system would have needed the boiler to be in a basement area to achieve the circulation.

The actual circulation through each rad will of course be provided by gravity aided by any injector tees.

The W/C curve will need to be adjusted to suit the characteristics of the radiator system.

 

[doitall]

The boiler can be on the same floorand still schieve circulation Tony.

Radiators are likely to be TBOE from normal tees or just sockett welded on the top of the pipe.

Think of the 3" pipe as the biggest LLH you've ever seen., the 3" pipe would have been the heat emitter when it was originally installed and the hall itself probably connected to the miners as a reading/rest/lunch room.

 

[OwainDIYer]

we do need to consider that a fairly elderly clientele use the hall and so may need to consider protecting the hotter pipes and rads against contact by them. Do skirting board levels pipes have to be protected like this as difficult to see how a person can easily touch one with bare skin unless stand against wall with no socks/trousers on.

They could however fall against the wall and slide down to the floor. A hot surface can burn even through clothing.

Against this risk you might consider that an elderly person might be unlikely to be in the hall on their own, so assistance can be given quickly, but in the toilet they might be undiscovered for a while. (Are there emergency alarms in the toilets?)

 

[echase]

Against this risk you might consider that an elderly person might be unlikely to be in the hall on their own, so assistance can be given quickly, but in the toilet they might be undiscovered for a while. (Are there emergency alarms in the toilets?)

Wow thanks for all the great ideas. Getting firms in for quotes so ideas are useful. Anyone in Winchester area want to quote? Send me a PM please.

To answer a few points, we are upgrading one toilet to disabled type so could add that alarm but suspect we will use a new low temp rad in that room. Apart from toilets there are no places a person can fall and be left unsupervised as there will be lots of people there.

Apart from the toilets and door frames where the pipe goes near the ceiling all of the pipes and boiler are close to floor level. I wonder if it was done that way to keep the hot pipes from being touched in these confined toilets.

Don’t think we have any thermostatic valves. So temperature control in the small rooms is not good. Looks like we should add them for any extensions to the loop. Generally its one big hall with a single wall thermostat in that space to control everything. Plus a temperature knob on boiler. Think it is the original 1960s boiler and the system was built for gas. The first and last rads are in the big room so any cool rads at end of loop is not a big problem. Middle of loop is the toilets.

Can someone explain weather compensation as I don’t understand what is does of whether we need it?

Generally the hall is used a few times a week for 2-3 hour periods. It spends most of time heating up and then the boiler goes off, so it is not at a stable state for more than an hour a day. We had a problem where after a few hours foir the few long meetings the temperature would fall off and could not be easily got back up again but I think that was just due a very clapped out wall thermostat not regulating at all closely.

One way to add the 2 extra rooms would be to add 5m to the loop which must be over 60m long already so adding 5m is not going to slow the flow. Or run a couple of metres of small pipe off the loop and put the rads in side room fairly high so it convects to it. Maybe even use high level fan convectors. Does that work or do the rads have to be very close to the loop pipe? Alternative may be to run a new set of 15mm pipes on another pump just for the side rooms. Could this be run off main loop as long as does not bypass one of the main rads, as getting these pipe back to boiler room is difficult? Concrete floor prevents underfloor piping.

 

[doitall]

Hi,

Wouldn't be interested in doing the work but if you want me to have a look when I pass you by then pm me an email address

Have two trips planned in November and two in December at the mo.