Help please – new boiler installation problems

[kalozo]

Hi,

I have just had a Remeha 30V installed on an open system. The system was working perfectly prior to the new boiler being fitted apart from a corroded heat exchanger. The installers were recommended by Remeha.

The job took over a week during which we had no hot water or heating when originally estimated at 1 day. On completion of the job I now have two issues that I am having problems resolving with the installer and would like some advice.

1) Wiring – the room stat light is now permanently on even when the heating is switched off. When I switch the hot water on the room stat light goes out. This definitely doesn’t sound right to me? There have been multiple attempts at the wiring…

2) Cold radiators – I now have 4 cold radiators in the system. The installer is refusing to believe that they used to get hot and has stated the only way to resolve is fitting a larger 15/60 pump. I have 16 radiators. I struggle to understand why the old pump is no longer big enough unless there is a new restriction in the pipework, an airlock or balancing issue?

I would really welcome any advice on how to tackle the two issues and resolve with the installer as we have reached an impasse – he will only accept me paying for the new pump and for him to have another attempt at the wiring. I have run out of confidence…

Thanks,
Chris

 

[erj]

system might just need ballancing, if not bigger pump, you paying? not happy.
He sorts the wiring out at his expance!
Have you payed him for the job? A week to do a days work sounds dodgie.
If you have not payed him get the man of the boiler out to make sure it is working OK and in right.
if OK give him one last chance to fix it, if he can not get some one in who can and take it off his money

 

[Heating-eng]

system might just need ballancing, if not bigger pump, you paying? not happy.
He sorts the wiring out at his expance!
Have you payed him for the job? A week to do a days work sounds dodgie.
If you have not payed him get the man of the boiler out to make sure it is working OK and in right.
if OK give him one last chance to fix it, if he can not get some one in who can and take it off his money

Sounds like system needs balancing from what's been said,

 

[SafeGasInstall]

did he change all the radiators valves on all the rads ! if so he will need to balance the system as just been mention ! Is installers duty to leave house and boiler with all controls working correctly ! Sorry to hear you had a such a bad experience with your remeha plumber !

 

[bengasman]

What does it say on the benchmark sheet under flow and return temperature?

 

[kalozo]

Thanks for the responses and apologies for the delay...

TRVs were fitted by a different engineer in March. All radiators got hot with the old boiler after fitting the new TRVs.

Boiler installer claims to have balanced the system.

The flow temp is 43'C and return 42'C.

I can force hot water to the radiators that aren't working by closing the TRVs around the rest of the house.

Thanks,
Chris

 

[doitmyself]

The flow temp is 43'C and return 42'C.

Those are very strange figures; they imply that the water is travelling so fast through the system that virtually no heat is being given off. Of course this could be due to the warm weather.

What was the weather like when the boiler was installed? Balancing would be virtually impossible to do with those water temperatures.

A 30V seems very large, even for 16 rads. What was the old boiler?

The wiring is definitely wrong. Can you give more information about the system - what other components are there, apart from the boiler and pump?

 

[bengasman]

The flow temp is 43'C and return 42'C.

Is that what you measure, or what it says on the benchmark sheet?

I can force hot water to the radiators that aren't working by closing the TRVs around the rest of the house.

He didn't balance the system; not surprising for somebody who quotes one day for installing a boiler.

 

[kalozo]

The original boiler was 26kw. I had three quotes and all installers quoted the 30V.

43 and 42 are from the benchmark sheet that the installer hand filled in. Weather on install was average 16-18'C kind of days. What would normal temperatures lool like?

The system is as follows:

1) Honeywell 3 way diverter valve
2) Grundfos 15-50 pump
3) Honeywell room stat
4) TRVs on all rad except 2 - one in hall where room stat is located and one small radiator in lounge used to provide background heat

There are 16 rads. The ones that aren't heating up are in an extension that was built about 7-8 years ago before we bought the house.

Installer is coming back today at 2pm to look at wiring and fit larger pump. We had reached an impasse on the pump and this was my only way forward. I haven't paid him for anything yet. So any suggestions/questions to ask him would be appreciated.

 

[Heating-eng]

sounds like the bypass is fully open if there the correct temp from flow and return

 

[kalozo]

What bypass? What should it be set too?

It is no surprise that the flow and return are similar temperatures as the radiators aren't really heating up to divert heat away from the return...

 

[aggis]

Take a look at V4073A Motorised Midposition Diverter Valve - Honeywell UK Heating Controls will link you to installation inst, & wiring diagragm. Bypass would go between pump & 3 way valve into return.

 

[doitmyself]

The original boiler was 26kw. I had three quotes and all installers quoted the 30V.

Typical! I bet your 16kW radiators don't add up to 30KW and they probably don't add up to 26kW either.

Use Stelrad Elite Catalogue to find out what each rad produces.

43 and 42 are from the benchmark sheet that the installer hand filled in. Weather on install was average 16-18'C kind of days.

So the boiler was doing virtually nothing to raise the temperature to 21C.

What would normal temperatures look like?

If you are going to balance the system correctly, you need a flow of 75C and return of 65C.

Honeywell 3 way diverter valve

Assuming it is the V4073 mid-position valve, the correct wiring diagram is on page 25 of the Avanta Schematics Book

 

[bengasman]

43 and 42 are from the benchmark sheet that the installer hand filled in. Weather on install was average 16-18'C kind of days. What would normal temperatures lool like?

That is so far off, it's not even funny. Should be 20 degree difference or there abouts.
The service and installation manual gives the exact recommended values. I normally aim for 70/50-ish.

 

[Heating-eng]

That is so far off, it's not even funny. Should be 20 degree difference or there abouts.
The service and installation manual gives the exact recommended values. I normally aim for 70/50-ish.

I thought it was 11 degree

 

[Mrs Tara Plumbi]

Yes it is 11 degrees C, which is 20 degrees F in old money. I think that's what bengasman is talking about. Gosh he must be so old!

 

[bengasman]

Yes it is 11 degrees C, which is 20 degrees F in old money. I think that's what bengasman is talking about. Gosh he must be so old!

It has been 20C since 2005.

 

[kalozo]

We have some progress. I have had the newer pump fitted (Remeha confirmed old pump probably to small for the boiler). Installer still couldn't get 4 radiators to work but I managed to chase an airlock round the system and bleed off at two of the highest radiators and they now all appear to be working. Thanks for all your help on this one...

Wiring - installer still says is correct. Just to recap... Room light stat is off. Put heating on room stat light comes on. Turn heating off and room stat light remains on. Turn water on and room stat light goes off.

Installer says that it will remain on because the diverter valve stays in position feeding the room stat until switching the water on causes the diverter valve to move and then light goes out.

It never used to do this with the old boiler. We have moved to 6 core wiring so this may have chaned things. However, I am still not convinced that the wiring is correct.

What do people think? I really need something definitive to challenge on otherwise I will have to let this drop.

Thanks,
Chris

 

[bengasman]

Installer still couldn't get 4 radiators to work but I managed to chase an airlock round the system and bleed off at two of the highest radiators and they now all appear to be working.

That is the second major blunder, are you sure this clown is really Gas Safe Registered?
At this level of incompetence, I would call GSR and ask them to verify all is safe. If he can't find an airlock, he may not have found a gas leak either, let alone understand how to set up the gas mix. This can lead to dangerous levels of CO.
Did he balance the system to achieve the temperatures as indicated in the manual? Failing to do this can result in an increase in your gasbill of around 10% for as long as the boiler is there until it is corrected.
Sad but true, cut your losses and get somebody else who can finish the job properly, it may cost some extra, but it is still cheaper in the long rung than leaving a cowboy job to deteriorate.
Another thing to do is a water test to make sure it is clean and of the right PH.

 

[doitmyself]

Wiring - installer still says is correct. Just to recap... Room light stat is off. Put heating on room stat light comes on. Turn heating off and room stat light remains on. Turn water on and room stat light goes off.

Is the stat light as bright as when the heating is on? If so, there is a wiring fault

Installer says that it will remain on because the diverter valve stays in position feeding the room stat until switching the water on causes the diverter valve to move and then light goes out.

The installer is correct when he says that the diverter valve stays in the CH position. There is feed back path from the valve to the stat, but it is at a reduced voltage - 100-150Vac, so the light should be much dimmer

Read How a mid-position valve works. Look at the diagram CH Satisfied and you will see the feedback path from the HW timer/stat grey wire via R2 and S2 to the CH stat white wire. R2 is a very high value, so the voltage at the CH stat should only be about 100 to 150V. It may be that this is enough to turn the bulb (probably a neon) on.

It never used to do this with the old boiler. We have moved to 6 core wiring so this may have changed things. However, I am still not convinced that the wiring is correct.

So it's the same valve, thermostat and timer, the only thing which has changed is the boiler and the wiring? Changing the boiler will not cause the problem to suddenly appear, so the only thing left is the wiring.

Has the installer followed the wiring in the link I gave earlier?

 

[bengasman]

If you are going to balance the system correctly, you need a flow of 75C and return of 65C.

Were you asleep when you did you part L compliance course, or did you start in this line of work last week? Do you actually read the manual before you install a boiler? Steamers need a return temperature of 55C or lower to work as designed.

 

[doitmyself]

Steamers need a return temperature of 55C or lower to work as designed.

I know that! But the complete system has to be designed to run with a 20C differential.

If you balance the system using a flow of 75C and return of 55C you will reduce the radiator output to 85% of their nominal output. So a newly installed system need the rads "oversized" by about 20%.

When you are changing the boiler on an existing system, where the rads were sized for an 11C drop, balancing the system so you get a 20C drop across the rads will immediately reduce the rad output by 15%. This may be acceptable to the owner, particularly if the house has been "improved" since the heating was originally installed - loft/cavity insulation, double glazing etc.

 

[bengasman]

If you balance the system using a flow of 75C and return of 55C you will reduce the radiator output to 85% of their nominal output. So a newly installed system need the rads "oversized" by about 20%.

When you are changing the boiler on an existing system, where the rads were sized for an 11C drop, balancing the system so you get a 20C drop across the rads will immediately reduce the rad output by 15%.

That is both incorrect and irrelevant.
What temperatures do you fill out on the benchmark sheet upon commissioning?

 

[Bartdude]

Where you asleep when you did you part L compliance course, or did you start in this line of work last week? Do you actually read the manual before you install a boiler?

Which charm school did you attend?This isn't the screwfix forum!

 

[bengasman]

Which charm school did you attend?

I did don't mince words when dealing with fools who pretend to be experts but in reality are cowboys or amateurs.
Doitmyself apparently likes to make it appear he knows it all, but clearly doesn't understand the very basics of ch install and design; every forum has them and at best they do more harm than good, but mostly they do no good at all.

 

[Gray0689]

I did don't mince words when dealing with fools who pretend to be experts but in reality are cowboys or amateurs.
Doitmyself apparently likes to make it appear he knows it all, but clearly doesn't understand the very basics of ch install and design; every forum has them and at best they do more harm than good, but mostly they do no good at all.

Your a bundle of joy today mate lol

 

[bengasman]

Your a bundle of joy today mate lol

This is the central heating section of UK Plumbers forum; I claim to be an expert on ch design and repair ( and can back it up ), not a clown talking nonsense in an attempt at entertaining people.
Others here on the other hand..........

 

[Gray0689]

This is the central heating section of UK Plumbers forum; I claim to be an expert on ch design and repair ( and can back it up ), not a clown talking nonsense in an attempt at entertaining people.
Others here on the other hand..........

Lol I'm a plumber I'm not an expert I can safely say I learn somthing new all the time when I know everything I'll call myself an expert and thats never going to happen and i don't mistake arrogance for skill
Yes you are corect in a condesing boiler needs a return temp of not more than 55c to work at it's optimum efficency why did you not try and educate the person that got it wrong instead of calling them a fool!!
Chill out and wise up

 

[bengasman]

Lol I'm a plumber I'm not an expert I can safely say I learn somthing new all the time when I know everything I'll call myself an expert and thats never going to happen

Agreed. I can't ( unfortunately ) say I learn something EVERY day about my work, but frequently; all experts do. Those who don't clearly don't keep up with the latest developments. ;-)

As to why I call the man a fool: what else would you call an amateur who thinks he knows better than a professional when his errors are so obvious that all anyone needs to do is rtfm to see what the facts are?

 

[doitmyself]

If you balance the system using a flow of 75C and return of 55C you will reduce the radiator output to 85% of their nominal output. So a newly installed system need the rads "oversized" by about 20%.

When you are changing the boiler on an existing system, where the rads were sized for an 11C drop, balancing the system so you get a 20C drop across the rads will immediately reduce the rad output by 15%.

That is both incorrect and irrelevant.

Ir certainly is not incorrect, though it may be slightly irrelevant to the OP's problem. The output of a radiator is related to the flow and return temperatures; it is not a fixed quantity.

 

[Heating-eng]

Agreed. I can't ( unfortunately ) say I learn something EVERY day about my work, but frequently; all experts do. Those who don't clearly don't keep up with the latest developments. ;-)

As to why I call the man a fool: what else would you call an amateur who thinks he knows better than a professional when his errors are so obvious that all anyone needs to do is rtfm to see what the facts are?

I have worked with central heating all my working life ( 21 years ) and I do not know everything and come on these forums for help.
Calling the guy a fool is uncalled for in my opinion.
Maybe just anwsering the question correctly with the facts would of been much better, this would also assist the plumbers and heating engineers that may of forgot the correct temp.

 

[doitmyself]

Deleted

 

[doitmyself]

fools who pretend to be experts but in reality are cowboys or amateurs.

And you are the guy who boasts on his website:

It was somewhere in my teens, that I "qualified" in the design, building and maintenance of wireless communication equipment.

What "qualifications" were they and how long did it take to acquire them?

 

[bengasman]

In my teens means over 30 years ago. I haven't got the slightest clue what it was called, and it has probably been superseded by something that has been superseded since. If you can come up with a half decent reason why it would be of any importance to heating engineer what courses he did 3 decades earlier in other disciplines, I'll have a look to see if I can find it.
In the mean time, your silence about how you commission a boiler speaks for itself.

 

[AWheating]

I did don't mince words when dealing with fools who pretend to be experts but in reality are cowboys or amateurs.
Doitmyself apparently likes to make it appear he knows it all, but clearly doesn't understand the very basics of ch install and design; every forum has them and at best they do more harm than good, but mostly they do no good at all.

an "expert" who thinks everyone who knows less then them is a fool should either help educate people in a non degrading manner or not bother to post at all IMO.