Has my builder ruined my boiler?

[Riley]

It was my understanding that you required two taps by regs anyway?

You can see why you have the NRV on the cold, as it's less of a dead leg.

And we have all seen proper filling loops with one tap on

 

[EvilDrPorkChop]

But there’s no dead leg because the hose should be removed

Should be. But how many customers actually remove it though.

Also if you're only fitting a tap on one side and just a NRV on the other I wouldn't be removing the link.

 

[Riley]

No but I’m arguing regs if you say there should be two taps then the hose should also be removed. Sorry I’m not being pedantic I’m genuinely querying. I cannot see what difference it makes what the reasoning is for the nrv on cold

 

[EvilDrPorkChop]

No but I’m arguing regs if you say there should be two taps then the hose should also be removed. Sorry I’m not being pedantic I’m genuinely querying. I cannot see what difference it makes what the reasoning is for the nrv on cold

I wasn't disputing the fact that the hose shouldn't be removed, I was just simply stating that hardly anyone actually removes the link.

I thought there was some reg about the NRV on the filling loop, but I can't find it to hand. Years ago, it was as you say NRV on the heating side. Then about 10 years ago I thought they changed it and required the NRV to be on the cold main. Incase someone left the filling loop open on the cold side and the dead leg within the loop.

Even if it isn't a reg about it, isn't it better practice for it to be on the Cold? You remove the dead leg (If one is created by the customer), plus you can drain the boiler easily when recharging the expansion vessel or maintenance .

Two taps - at least if one is passing you have a fail safe on your second tap.

 

[Riley]

Oh I totally agree with two taps don’t get me wrong but to me it’s logical to stop the heat at the return end so there is no inadvertent heating of the cold side. I cannot see where a dead leg occurs if there is no hose though.

 

[EvilDrPorkChop]

Oh I totally agree with two taps don’t get me wrong but to me it’s logical to stop the heat at the return end so there is no inadvertent heating of the cold side. I cannot see where a dead leg occurs if there is no hose though.

You're right, there isn't one when the hose has been removed. But my point kind of was, no one ever removes the hose.

 

[OffshoreGas]

Sorry to sound blunt but your title is immediately accusatory. If in fact it was a builder or a plumber that worked on the boiler and not a gas safe engineer then I’m afraid the fault lies with you

Why do you need to be gas safe to fit a zone valve?

 

[OffshoreGas]

Thanks Riley, the only problem I now have is, the extension build is new and I have not signed off on the builder's snagging list. So a small final payment is due. I don't know whether I should trust him to put it right or to call in a known good plumber to rectify his work.

Legally the original contractor is entitled to be given reasonable opportunity to put the situation right. You’re well within your rights to insist the work is undertaken by a competent person. Sounds very like you have the experience to decide for yourself if the guy is flanneling you.

 

[Riley]

Why do you need to be gas safe to fit a zone valve?

Didn’t say to fit a zone valve did I. OP alluded to the rebuild of the boiler which I was questionning

 

[Riley]

Legally the original contractor is entitled to be given reasonable opportunity to put the situation right. You’re well within your rights to insist the work is undertaken by a competent person. Sounds very like you have the experience to decide for yourself if the guy is flanneling you.

As you say however you are well within your rights also to refuse access if you feel they have acted outside scope or unlawfully

 

[OffshoreGas]

Didn’t say to fit a zone valve did I. OP alluded to the rebuild of the boiler which I was questionning

Sorry, I didn’t read it as the boiler had been rebuilt some time before the builder had worked on the system.

 

[OffshoreGas]

As you say however you are well within your rights also to refuse access if you feel they have acted outside scope or unlawfully

It’s generally not looked on favourably by the small claims court if you’ve refused to give a contractor fair chance to put right what may be an honest mistake.

Neither the pipework nor electrical work is notifiable under building regulations so not sure how you’d prove the guy wasn’t competent.

 

[Riley]

Again I was referring to whether or not the builder had acted unlawfully in terms of working on the boiler. They don’t get a second chance there

 

[OffshoreGas]

A 30s google search turned up the manual for your boiler, in section 1.6 it clearly stares the diverter valve must be open to fill the boiler. See attached image.

Doesn’t sound like your builders sub contractor has done anything wrong here.

 

[Welder]

Don't blame you for keeping it. I'm keeping my Glow Worm Ultimate going for as long as I can.

We've taken condensing boilers out which have been 6/7 years old which were beyond repairing. Admittedly these were probably ones that haven't been well maintained or fitted well.

My Ideal Mexico is of 1997 vintage

On a sep note, efficiency ratings as specified by all manufacturers are ONLY seen by a VERY small number of UK home owners.
Why?
The efficiencies are calculated at a flow temp of 50 degrees C and a return of 30 degs C. However, most UK home owners would claim the system is faulty at such low flow temps so new (efficient boilers) are commissioned to run at a flow of 70 & (at best) a return of 50. This delivers just a few % of potential and rarely (if ever) pays back the investment.

 

[OffshoreGas]

My Ideal Mexico is of 1997 vintage

On a sep note, efficiency ratings as specified by all manufacturers are ONLY seen by a VERY small number of UK home owners.
Why?
The efficiencies are calculated at a flow temp of 50 degrees C and a return of 30 degs C. However, most UK home owners would claim the system is faulty at such low flow temps so new (efficient boilers) are commissioned to run at a flow of 70 & (at best) a return of 50. This delivers just a few % of potential and rarely (if ever) pays back the investment.

How do you achieve that then?

Increase the resonance time/reduce flow rate through radiators?

Surprising in this day and age of smart TRVs there not measuring flow/return temp.

 

[Welder]

How do you achieve that then?

Increase the resonance time/reduce flow rate through radiators?

Surprising in this day and age of smart TRVs there not measuring flow/return temp.

Achieve what?

 

[OffshoreGas]

Achieve what?

The temperature differential across the radiator.

 

[Welder]

The temperature differential across the radiator.

Flow rate. Slower the flow rate higher the temp drop.

 

[Michael1960]

If I accept what you are saying and I bow to your superior knowledge. I don't need to call the builder back. I just need a competent Gas Safe plumber to investigate and fix the problem? Know any good and qualified trustworthy central heating engineers in the North West London area?

The emphasis being "plumber" or heating engineer !

 

[OffshoreGas]

The emphasis being "plumber" or heating engineer !

If you read the manual it says the diverter valve needs to be be open to fill. There doesn't appear to be anything wrong with the work tats been done.

 

[Chrisjones.7976]

If the cold water feed to the filler loop is boiler side of the new valves you should be able to pressurise the system. It's unclear what's where from the pictures. It needs a sketch of the pipework with valve positions. If you turn a tap into you get hot water? Too much guesswork without a diagram.

 

[OffshoreGas]

If the cold water feed to the filler loop is boiler side of the new valves you should be able to pressurise the system. It's unclear what's where from the pictures. It needs a sketch of the pipework with valve positions. If you turn a tap into you get hot water? Too much guesswork without a diagram.

The manual for the boiler clearly says the the diverter valve needs to be open to fill.

 

[Karl Murray]

Get someone out to check it?

No point any of us guessing as by the sounds of it you shouldn’t be touching it anyway.

Regardless looking at your pictures you don’t have a bypass for when both zones are closed. Who knows if you’ve got a non return anywhere on the system.

You’ve also got a combi so hot water demand isn’t with the zone valve.

You’ll need a professional to diagnose on site it in my opinion.