Vented to unvented - general queries

[Madrab]

Builder and plumber seem to be of the opinion that the pressure looks fine so we really don't need to check mains pressure.

Bad idea IMO - It's so simple to do a dynamic pressure and flow test - if the plumber and builder think it's fine 'just by looking at it' then I'd think twice about using them. It's as simple as getting a £15 pressure gauge, connect it to the outside tap and then run a couple of other cold outlets, time filling a bucket @ one of them for a minute and hey presto, that's the dynamic pressure and flow reading. If the plumber can't do such a simple test, doesn't have a pressure gauge and won't take all of 5 mins to do the work then IAH, I'd be looking for someone else.

Should that be prior to install or immediately after install?

system would be isolated from the current boiler and sealed and then pressurised and left for a period of time. The test should be performed anytime prior to the re-work.

 

[Agile]

Builder and plumber seem to be of the opinion that the pressure looks fine so we really don't need to check mains pressure. Not sure what to do there...trying to find an alternative supplier (who may be just as flaky) doesn't fill me with any great enthusiasm right now.

That seems to prove that neither of them have proper experience of the topic.

I suppose they just take the attitude that they are spending your money.

As far boilers are concerned any kind can heat a cylinder. Sometimes a combi is cheaper! Using a combi to supply just the kitchen can be a good idea too.

 

[ChrisJP]

It's quite outrageous to charge £2k extra to "guarantee" the work. Are they saying that if you don't pay this extra fee they'll do the work but so badly it likely won't work? I would run a mile from a contractor who adopts this approach.

 

[drives]

It's quite outrageous to charge £2k extra to "guarantee" the work. Are they saying that if you don't pay this extra fee they'll do the work but so badly it likely won't work? I would run a mile from a contractor who adopts this approach.

Built into the quote as an added charge and no option to opt out.

Here's the blurb from Heatgeek. As you say it is rather off-putting even if the overall charge they propose for all of the work (where it looks like these companies assume they might need to convert to sealed and add cylinder) might not be a million miles off...

The Heat Geek Performance Guarantee assures your installation will meet the efficiency stated in your system proposal at minimum. The installation will be remotely monitored and if it comes short of this efficiency, or unable get your home up to temperature on the coldest days of the year, we will upgrade your system as necessary completely free of charge.

The Heat Geek Installation Guarantee gives you peace of mind that if there are any unexpected issues we will send another vetted Heat Geek, trained to the same highest standards and adhering to the same code of conduct, to finish the job exactly as per the proposal, and maintain our performance guarantee.

 

[JonathanM]

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[ChrisJP]

How odd to add a compulsory surcharge to "guarantee" their work. It's like buying a new car and finding there's a compulsory surcharge to guarantee the engine has been installed properly and will keep running.
With any professional I would have thought the installing correctly and ensuring the system works as it should should automatically be part of the offer and built into their prices.

 

[Agile]

I would say that they know that the mains water supply may prove insufficient and they know that a sealed heating system should normally be used.

So they are fitting a lesser than ideal system to keep the cost down and explaining that they cannot guaranty against the need to do additional work in the future.