Wider central heating pipes for new boiler?

[aliciac]

Hello everyone!

I'm new here and I was looking for some advice about a new boiler. At the moment I have an old Vaillant combi boiler which I'm told by an independent heating engineer, who I've always used, is over 20 years old. It's been fine for as long as I've remembered but recently I've been having some problems with it and am looking to get an upgrade.

Central heating and hot water from all taps is fine but I'm not getting hot water to a thermostatic mixer shower. Turning on the shower does not kick start the boiler (the small pilot flame just stays there), but turning on any tap or central heating does fire up the boiler. So at the moment, I switch on the central heating, have a shower and then turn the central heating off. This seems to work, I do get hot water in the shower using this method, but the shower alone will not fire up the boiler. I've had the shower replaced with a new one, but the problem persists and so have ruled out a faulty shower.

My heating engineer could not resolve this issue despite trying to adjust the pressures, and recommended a new boiler which of course would save me money on heating bills in the future. After reading some posts on this website, I understand I may need a new 22mm gas line to the new combi boiler, which the heating engineer mentioned, but he also said I would need new pipework to all of the radiators in the house because the pipes were only 15mm thick and this would cause some sort of lock on the new boiler. There are four 15mm pipes for central heating going into the boiler. There are a total of 5 radiators. 2 bedrooms, lounge, kitchen and towel radiator in bathroom. However I cannot find any talk of new pipework to radiators here.

Is this extra work really necessary? Not just worried about the extra cost, but also the hassle of having to pull up flooring etc to lay new pipes.

Would really appreciate some advice!

Thank you so much!

Alicia.

 

[Gas2Air]

Gas pipework upgrade yes. 15mm to rads is fine.

 

[Dan Robinson]

5 rads is pushing it a little. We work to no more than 3 rads potter 15mm run.

Although it doesn't sound like your engineer has tried very convincingly to repair your old boiler.

Where in the world are you?

 

[GavThePlumber]

One post users do not deserve a reply on such a topic, it generates confusion.

 

[aliciac]

Thank you very much for your posts Gas2Air, Dan_Robinson and GavThePlumber. I've got a flat in Liverpool. Just wanted to know if the work was necessary or totally out of the ordinary. Now I know it's recommended but perhaps not strictly essential (I presume boiler make and model dependent), I can make an informed decision based on the costs of laying new radiator pipes. Rest easy GavThePlumber, no confusion caused.

Thanks again, appreciate you time!

Alicia.

 

[oldbuffer]

You might want to consider why the central heating and hot water to all but the shower works OK before considering a replacement boiler. Assuming it has one, if the hot water inlet filter to the shower is partially blocked, turning the shower on may result in insufficient hot water flow to fire the boiler.

While a twenty year old boiler is probably approaching the end of its useful life, you might get a bit more life out of it for what might only be an hour or two of a plumbers time.

 

[aliciac]

Thanks very much for your post oldbuffer! The thermostatic mixer shower replaced an old electric shower recently when the whole bathroom was refurbished, so new pipes were installed for the mixer shower. We thought the new mixer shower could be faulty, and so exchanged it, but the same issue arose and the plumber insists the pipework to the shower is correct and is new. Not sure if there's a hot water inlet filter to the shower, it's a Triton Tesla shower.

I do have a maintenance contract with British Gas, and called in an heating engineer to inspect the boiler too. He said the problem was likely within the heat exchanger, possibly clogged up. Looked on his laptop and the part is no longer available for this model. So recommended a new boiler. I guess I could call in another independent heating engineer to get a diagnosis and see whether it's economically viable to fix this boiler.

Thanks again for the post!

Alicia.

 

[chantelle]

I do have a maintenance contract with British Gas, and called in an heating engineer to inspect the boiler too. He said the problem was likely within the heat exchanger, possibly clogged up. Looked on his laptop and the part is no longer available for this model.

He is a liar and the heat exchanger can be descaled, British Gas are thieving, deceitful Arthur Daley`s working under a badge whom you trust,the heat exchanger can be replaced for this model, he is again a liar.Take Bg to court, first get there findings and recommendations on paper,take it to an independent heating enginneer and sue them. Simples.

 

[Dan Robinson]

And what model would that be?

 

[chantelle]

Vaillant combi. Get parts for every model every day.British Gas poster boy. Wake up and smell the coffee,automaton,thousands just like you,

 

[Dan Robinson]

You think I'm a British Gas poster boy?

You truly are mental m

I'm far too good looking.

 

[Agile]

If only anyone had read the original post they would have seen that the boiler is fine!

It supplies hot water to all the taps. In that case it can only be the shower which is faulty or if it has never worked then its been badly installed.

I have no confidence in this plumber who cannot understand a very simple situation and just wants to install a new boiler. Funny how so many plumbers only want to fit new boilers!

Tony

 

[Dan Robinson]

Although it doesn't sound like your engineer has tried very convincingly to repair your old boiler

 

[doitall]

Have to agree with Agile certainly sounds like a shower problem if all the taps work just fine

 

[aliciac]

Thanks again for the replies guys! The model is Vaillant VCW-Sine 18 T3W. Yes, very old, but still going, except for the shower bit of course! We did think the issue was with the shower because we were getting hot water and central heating. As soon as any hot water tap is opened even slightly, the boiler fires up. Just won't fire up for the shower! So we did get another Triton shower, they're supposed to be a good brand I've heard, which didn't solve the issue, so that can only leave the pipework. As soon as the central heating is switched on, or a hot water tap opened even slightly, the shower supplies hot water, it just won't supply hot water on its own! I presume because it does provide hot water with help, the piping to the shower is correct? And there's something wrong with the pressures in the pipe work to the shower or within the boiler?

At the moment we're using the central heating work around when taking a shower, but I will get another independent heating engineer to look at it next week before forking out for a new boiler, because you guys seem to be persuaded that the boiler still has life in it yet!

Thanks to all who've spent time and brain power on my issue!

Alicia.