New Boiler Problems

[ezza]

We had our 18 year old boiler replaced last year after the annual service. Having had a big quote we got it replaced by a family friend. The official survey identified that our 'tank' is in fact a thermal store the guy who fitted the new boiler is having a few issues and I was wondering if there are any common problems with thermal stores which he needs to look into.

The issues we've had thus far are:

1) When the boiler was first fitted it constantly tripped with a "flow pressure" error. He's since replaced the pump.

2) Noisy system, banging pipes but also 'odd' noises from the boiler.

The system now gives a lovely warm house. However we still get a lot of noise. Also when the Hot water is on some of the radiators go cold. Additionally while the water initially comes out hot with the hot tap on hard it goes a lot cooler fairly quickly. With the shower on low it's possible to get a reasonably hot shower but if you turn it up all the way it's way too cold.

Also if I leave the hot water off, there's still hot water in the system so I can still run a bath. If I do this the noise in the system is reduced.

Any help gratefully received. The system was golden before we changed the boiler. Is there a chance that the boiler we have is no good for use with the store?

Cheers

 

[Agile]

Most modern boilers are designed for pressurised systems.

Most thermal stores are designed for open systems.

It mab that the unspecified boiler model is not suitable for the installation.

Boiler should be fitted by gas registered people.

It sounds as if your family friend did not have a clue as to what he was doing! My advice would be to get it inspected by Gas Safe ( free ) or by a competent boiler engineer.

I hope you did not pay this friend. Its illegal for him do do any paid gas work and still pretty illegal to do any except in his own house!

As we so often read on here, it seems like another case of trying to save money with an unqualified installer has backfired and may end up costing more than a professional!

What do we have to say to get people to use a qualified professional?

Tony

 

[ezza]

Hey Agile, thanks for the feedback.

For the record the family friend is fully Gas safe registered and it's his job. Of course I paid him or rather I paid his business albeit he did the job for me at reduced cost.

However I think he may have underestimated what the job entailled and has perhaps given us the wrong type of boiler. When he came to look after we had the first problem he suggested changing the tank which I was obviously against.

When I get home I'll have a look in the boiler manual and see if it says anything about working with our thermal store.

The repair we've already had made to the boiler was carried out by a service engineer sent from the boiler manufacturer. I would have expected him to pick up if there was an issue with the boiler working with our system.

Still I will check.

Thanks

 

[wetshoes]

What make and model thermal store is it ?

 

[ezza]

Absolutely no idea. I'll have to look when I get home tonight.

 

[kevindgas]

What make and model thermal store is it ?

more relevant is what boiler is fitted?

 

[ezza]

The boiler is a Main HE24:

http://itemlistings.ebay.com/sdcsrp...21&mt_id=635&kw=main+24+he+best+price+boilers

The manual says:

"The boiler is suitable for use with fully pumped open vented and sealed systems with an indirect coil type high efficiency cylinder".

Sounds like it might be okay actually.

The cylinder has no markings on it that I can see. I think it was fitted when the house was built so it's probably 18+ years old.

Any more help gratefully received.

 

[wetshoes]

Can you describe the cylinder, how many pumps ? any other valves etc etc
-or post a photo of it ?

 

[ezza]

View media item 18469
Not the best pic I'm afraid and not sure it will help but there you go.

There's a Grundig pump down on the left hand side (purple)

 

[wetshoes]

Looks more like a combination cylinder than a thermal store to me !

 

[wetshoes]

Is your hot water pressure from the hot taps very good (almost mains pressure) or pretty poor ?

 

[ezza]

very good, as you say almost mains pressure

before the boiler was changed it was the same but much hotter.

 

[Agile]

Thats much better to now hear that the installer was indeed registered and that the boiler is designated as suitable for vented systems.

Its not a very complicated system and any half competent installer should not have too many problems.

The only question now is why its apparently not performing correctly.

To properly advise you I would need you to be able to measure the flow and return temperatures at the boiler while its heating the store.

It may well be that it only needs setting up properly. A photo of the boiler connections and those at the culinder posted on here would probably tell us a lot.

One feature of a condensing boiler is that its designed for a maximum flow temperature of 75° compared with a standard boiler's 82°. having said that HW should be supplied at no more than 60° to avoid the risk od scalding.

Tony

 

[wetshoes]

"Additionally while the water initially comes out hot with the hot tap on hard it goes a lot cooler fairly quickly."
This could be a faulty mixing valve, Is there a valve with 3 pipes going into it & an adjustment knob, hidden behind the red cylinder jacket somewhere ?

 

[kevindgas]

View media item 18469
Not the best pic I'm afraid and not sure it will help but there you go.

There's a Grundig pump down on the left hand side (purple)

good enough to show that it is a combination cylinder not a thermal store

the cylinder works by cold water in the top 10" the lower part is connected by a tube from the base of the top tank to the base of the bottom tank.

the heating passes through a coil in the lower tank and indirectly heats the water, hot water is then drawn off from the top of the bottom tank

if it is not hot then the following may be the trouble

blockage in the coil (check flow and return should heat up to similar temp in around 5 mins from cold)
Large amount of scale in the hot tank part (reducing the amount of water)
or the cylinder stat is set too low or isn't working correctly.