Yet another change of plan

[dawoodseed]

About a year ago we began planning on changing the heating system, I immediately came to this group for help.

At first the plan was to go for a standard 30kw combi boiler and just live with the poor flow rates experienced when two taps are opened at the same time. Then I thought why live with difficulty if you dont have to?

So the plan changed and I planned on getting an unvented cylinder with a system boiler, the plan stayed like this for months and I done lots of research before actually calling an installer. The first installer came along and measured the cold water flow rate, me being my stupid self forgot about doing that. In turned out that the flow rate was only 23lpm which wouldn't be sufficient for the unvented cylinder and worst of all even if I got an unvented cylinder it would not fit in the narrow airing cupboard!

So we decided on getting a vented cylinder with a system boiler because we also wanted a radiator in the loft.

Then the next installer came and checked the cold water flow rate and the hot water flow rate, the hot water flow rate was only 7lpm. The installer said that if we got an unvented cylinder it would still be better than what we got despite the 23lpm flow rate. So we decided on getting a storage combi (Vaillant ecoTEC plus 937) which gives 20lpm and when the store is depleted 15lpm.

One installer said that if we channel the concrete floor for the copper piping the copper piping will corrode and it will burst. Is this true?

We also want the new boiler to run two different heating zones, is this possible with a combi? The Vaillant VRC 430 weather compensator can run more than one heating zone so that's not a problem.

And finally the Vaillant weather compensator plugged into the boilers control panel and requires no room thermostat (according to Vaillant) so how does it know when the target temperature has been reached?

Thank you for all your co-operation, and special thanks to: Andy Hall Ed Sirret Roger Mills Owain The natural Philosopher

[JD]

That depends on how much you want to spend.

He's the expert so why are you checking with unknown people in a newsgroup as to whether he has told you something correctly. One of my relatives has had to take a concrete floor up in his kitchen because two pipes burst underneath it.

I thought you had companies in - didn't you ask them?

Why don't you contact the company?

It seems like you asked people to give you quotes, but didn't tell them what you wanted, didn't take their advice and don't know what you want! Get storage heaters.

[Dave Liquorice]

Concrete will corrode the copper (eventually) but that is simply solved by not letting the concrete touch the copper. Sleeve it inside plastic or wrap with denso tape. You need the pipe to be free to move for expansion/contraction anyway.

[Ed Sirett]

Yes. But, it begs the question why he didn't offer you some alternatives like:

1) Using plastic pipe. or 2) Corrosion protecting the copper pipe. or 3) routing the pipes elsewhere.

Yes. If any installer says they can't do it then show them the door, it means they aren't able to wire up basic S-plan heating controls.

I'm not familiar with this product. I would have thought that Part L of the building regs would still have to be met thus requiring some sort of internal temperature control.

[dawoodseed]

It seems that all the information I provided is not enough for you.

One installer said that it is very hard to run two zones with a combi boiler. The installer who told me about the concrete floor wanted to run the pipes along the skirting board, I thought he might be looking for a easier way to run the pipes so I was making sure by asking in this newsgroup.

And as for the last question, you are correct I should and I will ask Vaillant.