My new boiler-an expensive mistake?

[homeowner]

Hi All

Why oh why did i not come on this forum BEFORE getting a new boiler?

Recently replaced Ariston Micro Genus 24 with Vaillant Eco Tec 24. Previously I had a weakish hot water flow and assumed that with a new, efficient boiler, this would improve.

The old one gave 9 – 11L per min. I had considered an Eco Tec 28 to give me a better flow but was advised that my pipework may not accommodate the increased pressure. So I stuck with a 24.

So I was gutted to find that my flow on the Vaillant is now reduced to the point it is barely an unbroken stream. It is so weak , I can barely run a shower even with my tiny aquatiere showerhead. Running a bath takes so long that by the time you have enough water it has started cooling.

I had the flow measured at sure enough the bath is giving 9L per min. I was told the boiler is factory set to give only 9l. Why then does the kitchen show 11l?

Then I was told Thames only has to provide a 9L flow – but why then did I get a stronger flow on my old boiler, around 11L? What has Thames got to do with the specs of the boiler?!

Is there anything I can do with the existing set up to increase my flow?

Or am I looking at another boiler? I am gutted as this expense came at a bad time and I am hardly in a position to incur further expenses, but as I minimum, I need food, a warm bed, and decent showers!

Can any experts out there please advise what my options are?

 

[Masood]

Welcome to the forum, homeowner, and sorry to hear your tale of woe!

You were slightly misadvised on a couple of facts. The A 28KW boiler would not pressurise your pipework any more than a 24KW one would. Pressure and flow rate through a combi are largely to do with what mains pressure you have, although the heat exchanger in the boiler will affect it slightly.

As for the factory setting being 9L and your sink giving 11L, again, this is wrong - the manufacturers quote a certain temperature rise at a given flow rate eg. 9L at 35 degree temperature rise, as a performance benchmark. Not as a limit to what the boiler will put out. So you may well have 11L at the sink, but at a marginally lower temperature.

All that being said, if you're getting 11L at the sink, then it's not the boiler restricting you to 9L at the shower. I'd look at the inlet filter in your shower tap (if there is one), the pipework, and whether the shower head is clogged with limescale.

If your incoming mains pressure and flow rate is poor there are ways to improve it but really that needs a professional to assess what you've got, discuss the various options and suggest the best way forward.

 

[Ray Stafford]

Previously I had a weakish hot water flow and assumed that with a new, efficient boiler, this would improve.

This is a misapprehension.

You have replaced an older less efficient 24kw boiler with a more modern, more efficient (and in my opinion, better made) 24 kw boiler.

The important thing here is the 24kw. All other things being equal, the flowrate of a combi boiler is a direct function of its output. Going for a more modern, posher one might make it break down less often, it might reduce your gas bill, but 24 kilowatts is still 24 kilowatts.

So there was no way that going from the Ariston to the Vaillant was going to improve your flow rate. Equally, it should not have made it any worse, so any perceived degradation in performance can only be caused by one of three things:

1) Your new boiler is not set up properly or
2) Something happened during the course of the installation to the rest of the system (for example, some rubbish getting dislodged and settling in the inlet filter to the shower as Masood suggests)
3) All combis perform less well in winter than in summer, because the incoming main is at a lower temperature. Bearing in mind that you had also had an expectation that your new boiler would provide a better flow rate, you might be comparing the real output in winter with your idealised expectation - the best your old Ariston ever did (in summer) uplifted by your expectation of improved performance.

 

[basildog]

It may be a bit late but was your flow and pressure all checked before the new boiler was fitted ?
Seems to be more and more that the easy option is fit a combi no matter what and I am afraid often a combi is not the way to go ?

 

[Ermintrude]

You could install a cylinder and headder tank and a booster pump and use as a conventional system or an DHW booster set.

 

[Kemble]

The odd thing is... usually the only thing a combi does well... is a shower !

How high above the road are you ? Some flats should really have had boosters fitted or even holding tanks on the roof... but the developers avoid the extra cost...

 

[homeowner]

It cannot be my pipework as the old boiler gave a better flow. It also proves that with a 24kw you can get a decent flow, like i had on the old one.

My shower head is the tiniest and is 2 months old. Why would it work fine on day on the old boiler and literally not work properly the next day on the new boiler? It just a hand held type propped up on the wall - i'm not sure where i should be looking for anything causing a blockage, i dont think i have an inlet filter

It is very obvious that the pressure has dropped all round; hot and cold it seems, but obviously more noticeable on the hot. I could always have a decent shower on the old boiler

The water sprayed out and down - now i have to stand right up against the wall for the water to hit me.

I have a small house on the same level as the road. The bathroom is upstairs.
Alot of what people are suggesting here is going over my head

Whoever said there may have been an issue with quality of installation could have a good point - but what can i do about that? Shall i try and get Vaillant to come out under the warranty and say i dont think it was installed properly? They will probably tell me to go back to the installer, which i already have


In any case, I cannot live with this, so please break it down for me in terms of order of action points:

I'm thinking try and get Vaillant out under the warranty, if no luck, take out a loan and get another boiler?
And if so, do I get a 28kw?
This is probably the most expensive mistake I have ever made, I am GUTTED.
How do I make absolutely sure I do not get screwed a second time?

 

[homeowner]

PS. no flow and pressure was not checked before - although i said several times i was looking for better flow and that the hot tap in bathroom was not great.Of course, now i'd give anything to go back to what i had

 

[Billy Bob Bob]

get one of these problem sorted Salamander Home Boost - Mains Pressure Booster Pump | eBay

 

[Leo21]

Daft as it sounds, check your stop tap is on full. Are the cold taps noticeably slower as well?
the chances are its not boiler related, I fit loads of 824's with no issues. Having a bigger output boiler does affect your gas supply pipe and sizing.

 

[TBServices]

get one of these problem sorted Salamander Home Boost - Mains Pressure Booster Pump | eBay

Not necessarily.

 

[Billy Bob Bob]

Not necessarily.

if it can boost a 30 kw,then a 24 wont be a issue can you voice your reasons please

 

[Ch4 plumbing]

Gas man have you fitted many of these?

 

[Billy Bob Bob]

Gas man have you fitted many of these?

3 of them they seem to sort the issue out

 

[Masood]

It cannot be my pipework as the old boiler gave a better flow. It also proves that with a 24kw you can get a decent flow, like i had on the old one.

My shower head is the tiniest and is 2 months old. Why would it work fine on day on the old boiler and literally not work properly the next day on the new boiler? It just a hand held type propped up on the wall - i'm not sure where i should be looking for anything causing a blockage, i dont think i have an inlet filter

It is very obvious that the pressure has dropped all round; hot and cold it seems, but obviously more noticeable on the hot. I could always have a decent shower on the old boiler

The water sprayed out and down - now i have to stand right up against the wall for the water to hit me.

I have a small house on the same level as the road. The bathroom is upstairs.
Alot of what people are suggesting here is going over my head

Whoever said there may have been an issue with quality of installation could have a good point - but what can i do about that? Shall i try and get Vaillant to come out under the warranty and say i dont think it was installed properly? They will probably tell me to go back to the installer, which i already have


In any case, I cannot live with this, so please break it down for me in terms of order of action points:

I'm thinking try and get Vaillant out under the warranty, if no luck, take out a loan and get another boiler?
And if so, do I get a 28kw?
This is probably the most expensive mistake I have ever made, I am GUTTED.
How do I make absolutely sure I do not get screwed a second time?

Action point 1 - don't dismiss advice given out of hand!

The size, location and method of mounting your shower head is irrelevant. There may have been some installation debris pushed up into the head. It's the first place I would look.

2 - Forget a bigger boiler. Just forget it completely. You've had THREE very detailed explanations, in layman's terms, of why it won't help.

3 - It CAN be your pipework, as you pipework WILL have been modified to accommodate the new boiler - it hasn't just dropped straight on to the old connections.

If things are going over your head, call in a professional and ask them to do a proper investigation. As Leo said, it could be as simple as your stop tap being partially closed, although as you report 11L/min at the sink, that might not be the cause.

At least with a full check and report you'll have something to go back to the original installer with.

 

[TBServices]

if it can boost a 30 kw,then a 24 wont be a issue can you voice your reasons please

If the main cannot pass 12l/min because its restricted, I.e, its not a low pressure problem, the pump won't help.

Speaking from experience.

 

[Worcester]

It is very obvious that the pressure has dropped all round; hot and cold it seems

Bit of a clue there....

Cold pressure also down ....

So it isn't likely to be the boiler.

Could be the stop valve was turned off for the installation and is now actually broken and part closed so now isn't opened properly.. (happens quite a lot on old stop cocks)