Combi install? Corner cutting?

[CONFUSE]

Having a vaillant combi system installed next week.Is there anything i need to ensure the engineer does,to make sure he is not cutting corners!.I have heard rumours about having to have a rad on all the time on some cheaper installs! However mine is not cheap!!.Ps they are removing an ancient back boiler fire.Thanks.

 

[Gasman1015]

Glad I'm not doing it for you, nothing like customer distrust before you even start the job.

And as for a customer telling me what I have to do, defies comment.

 

[CONFUSE]

didn't mean to upset anyone! .Just wanted a few pointers thats all!

 

[chrishutt]

Download a copy of the installation and commissioning instructions from the Vaillant web site. Study this, and post for explanations of anything significant that you don't understand. You can then follow the installation procedure from an informed point of view.

The things most likely to be skimped on in a combi installation include:-

1. Thorough flushing of existing system to remove corrosion products and other debris that could cause damage to new boiler, using appropriate cleaning chemicals and finally inhibitor - this alone could take a day.

2. Replacing existing 22mm hot water pipework to 15mm. If 22mm is left in use, hot water will take longer to reach those taps supplied by it.

3. Upgrading gas supply pipe to ensure inlet working pressure of 20 mb.

4. Proper commissioning including checking gas pressures, flow and return temperatures, hot water flow rate - ensure Benchmark form is properly filled in with accurate data.

5. Can anyone add anything to this list?

 

[ollski]

Having a vaillant combi system installed next week.Is there anything i need to ensure the engineer does,to make sure he is not cutting corners!.I have heard rumours about having to have a rad on all the time on some cheaper installs! However mine is not cheap!!.Ps they are removing an ancient back boiler fire.Thanks.

lots of tea or coffee....gives you an excuse to keep a bit of an eye on things without the installer feeling you are standing over him...some older combis used a radiator as a bypass, but not any more.

 

[CONFUSE]

Thanks for the info.Never knew about the pipe upgrades needed!Do you mean the hot water piping will need renewing all the way to the bath as mine is the larger piping.?.Just downloaded that info from vaillant,52 pages!.Good bedtime reading!.Thanks again

 

[ollski]

Thanks for the info.Never knew about the pipe upgrades needed!Do you mean the hot water piping will need renewing all the way to the bath as mine is the larger piping.?.Just downloaded that info from vaillant,52 pages!.Good bedtime reading!.Thanks again

If he has quoted you for it, it's a recommendation rather than a requirement.

 

[chrishutt]

The replacement of 22mm pipework with 15mm will probably not be done unless specified as part of contract. But it can make a big difference.

For example, if your boiler has a flow rate of 12 litres/min and the pipe run to a hot tap is 10 metres, it will take 7 seconds to displace the cold water in a 15mm pipe, but 16 seconds to displace water in 22mm pipe. So that's an extra 9 seconds of waiting each time the tap is used. Assuming 10 uses per day, that's a total of 9 hours per year!

 

[ChrisR]

I hope he has checked your water mains pressure and flow. Ask him what they are. If the static pressure is much less than 2 bar, or the total cw flow (add kitchen and outside taps together) less than about 16 litres per minute, you will notice the effect
Which can be that upstairs taps don't produce any/much water if downstairs ones are open. He should have made sure you're aware of limitations of combis.

 

[Gasman1015]

didn't mean to upset anyone! .Just wanted a few pointers thats all!

Yes, it does annoy me.

Have some faith in your chosen installer.

Having said that, I would have expected the guy to have explained what is required to bring your current system upto spec. including the need to upgrade the gas supply and check your mains pressure and flow, aswell as advising you on the limitations of combi's.

I would have expected you to have written confirmation of what is being carried out and if you are so worried about cutting corners, that you should question your installer personally of anything that concerns you before work commences.

You state its not cheap, but then you are a Yorkshireman.

 

[htgeng]

lots of tea or coffee.

and a plate with biccies and/or kitkats never go amiss either. you always remember those customers!

 

[ArtfulBodger]

Download a copy of the installation and commissioning instructions from the Vaillant web site. Study this, and post for explanations of anything significant that you don't understand. You can then follow the installation procedure from an informed point of view.

The things most likely to be skimped on in a combi installation include:-

1. Thorough flushing of existing system to remove corrosion products and other debris that could cause damage to new boiler, using appropriate cleaning chemicals and finally inhibitor - this alone could take a day.

2. Replacing existing 22mm hot water pipework to 15mm. If 22mm is left in use, hot water will take longer to reach those taps supplied by it.

3. Upgrading gas supply pipe to ensure inlet working pressure of 20 mb.

4. Proper commissioning including checking gas pressures, flow and return temperatures, hot water flow rate - ensure Benchmark form is properly filled in with accurate data.

5. Can anyone add anything to this list?

Ensure that a roomstat suitable for a combi is fitted.
Ensure that all all rads except that closest to the stat have TRVs fitted
Check the docs for flue installation compliance

 

[Diyisfun]

Gasman1015

Glad I'm not doing it for you, nothing like customer distrust before you even start the job.

And as for a customer telling me what I have to do, defies comment.

If you are happy that your work is done to as it should be, what is the problem.
The question was straight forward, just asking for pointers.

So if a customer asks you if you have done A,B,C. How do you react.?

 

[Gasman1015]

When I survey the the job, I will explain in detail what has to be done and explain to the customer why it is required. I encourage questions on any and all points and make myself available for any questions that may arise.

I respect my customers and expect the same in return.

If they have to resort to asking for advice on a site such as this, then I have failed before I have begun.

 

[Agile]

The reality of the world is that you can explain clearly everything about a new installation and the client, a music teacher, woodworker or cleric has no chance of understanding more that 30% of what you are telling them.

Add the fears generated by rogue plumbers and its not surprising that we get posts like that above.

I spoke to a new client today and said that I would send an engineer to repair his boiler. He was noticably upset and said that he wanted me to come myself because I had given him confidence.

Starting a boiler install today, the client was disappointed that I was not doing all the work personally even though the eng had NVQ2 in plumbing and five ACS categories and was well educated and polite and over 40!

Tony Glazier