can anyone recommend a boiler for a single pipe system?

[Marc86]

i realise it should really be updated but the customer will not be told and there paying at the end of the day i have fully explained but sticking to there guns...

if anyone could recommend a system boiler for this installation if youve fitted one before or wat have ya woud be great cheers!

 

[transam]

I have installed a few boilers on single pipe systems , really old iron piped systems , but I have always used a plate exchanger , e.g there is no direct connection to the boiler , heating system remains open , boiler is sealed !!

 

[adlplumbing]

no i never had dealings with one try ring up few makes and and see if they have any compatible boilers

 

[AfterburN003]

I dont know of any combi boilers that will work on one pipe systems.

 

[transam]

If you use a plate exchanger , you only need to ask the manuf' if there boiler can be used for this purpose , boilers I have used on single pipe systems with this method are Biasi never asked them , Johnson & starley they said it was O.K , Raven heat they said it was O.K BUT , dont use them , the advantage to useing a plate exc' is the manu ' cant start gripeing about there warranties , or the state of the system water e.c.t , as the boiler is not connected to the existing circuit .

 

[Agile]

Manufacturers dont recommend them because wrongly achieved they give rise to problems which the installer cannot solve and in turn blames the maker.

All I can say is that a skillful and experienced installer can often make a one pipe system work quite well.

I fitted a new boiler to a small 15 mm system with some extra parallel rads added as well.

My friend recently fitted a Viessmann 100 to a 22 mm single pipe system with a little advice from me and he says it worked well. But I have not been back yet to inspect the installation and measure the operating conditions.

Tony

 

[gas4you]

I've got one coming up in a couple of weeks.

I'm fitting a Broag system boiler to it.

Due to the nature of the building and the ancient 'character' radiators, it has not been possible to re-pipe the system.

I will just have to 'suck it and see'.

As long as the flow rates are ok and the system balanced as far as possible, I see no forseeable problems, other than the general inefficiency of a one pipe system.

I have, as per usual, included a clear disclaimer in my quote, that any faults or design problems in the existing system are not covered under any warranty offered by me or the boiler manufacturer.

 

[Agile]

The potential difficulty of fitting a condensing boiler as a replacement to a one pipe is that the old system was working on a flow temp of perhaps 85° and a return of 75°.

Many current boilers dont give much more than the high seventies and even if you set the return to be the high sixties ( thus not condensing much ) the the last rads in the loop will be significantly cooler than before.

Many one pipes were based on a design bedroom temp of just 19° so undersized rads are a distinct possibility.

Its vitally important that full loft insulation and double glazed windows have been added so the heat loss has been reduced a bit to compensate.

Tony

 

[Johnny8718]

Hi All.

I have experienced the opposite. I had a firm give me a quote, stating that I could have a new combi without having to change the pipework, saving me about £500 on the bill.

Problem now would appear that the pump in the Potterton Apollo is much more powerful than the pump which was connected inline to the 22mm pipe from the Baxi back boiler. This in effect is firing the water around the circuit at such a speed that the radiators are only getting hot-ish.

The plumber will be coming back at the weekend to remove the pipe at the bottom of each rad to make the system what will be in effect, serial. I'm not unduly concerned about this as I can have the room stats removed and have a system which more or less works?

Does all of this seem plausible?

John.

 

[ALEC1]

were the valves changed? if so were they high lift valves for one pipe systems?

 

[Johnny8718]

The valves are the same as were fitted when we had the back boiler.

I have removed the room stat tops and have ensured that the plungers are all out.

Is it worth looking at this then?

 

[ALEC1]

higher velocity of the pump should enhance performance as the differential pressure will be greater between the flow and the return of each radiator...

are you leaving the boiler on pump on long enough?

so I doubt that that is the issue,

Do you happen to remember how high the boiler stat was with the previous boiler?

 

[Johnny8718]

Mmm. Struggling to answer really. I dont know much at all about the old boiler, specs etc etc.

As for the pump now, again not sure. One thing that I have noticed is that the pump is running continously when the heating is on and does not shut off at the moment.

 

[ALEC1]

what is the boiler thermostat set at...as said it shoukd be pretty well on maximum..

 

[Whitespirit66]

Isn't there a chance that removing the pipe from below each rad, which will mean they're in series, create problems all of it's own?