Boiler/hot water problem

Pauls

Before I start, I'll just make it clear that I do not intend to tamper with my boiler, I'm just trying to get an idea of what my problem could be. We've got an appointment for worcester to come out and inspect the boiler on tuesday but I'm not sure if it's a boiler problem or a 'muppet for a plumber' problem.

Basically we've just had an extension built and have had our combi boiler re-positioned and ever since we have had problems with the pressure on the the hot water supply. Literally I cannot turn on 2 taps at the same time, even if i turn on the cold tap any hot tap that was running will simply stop flowing.

Our boiler bloke has replaced a couple of random parts, charged us 2 days labour and still not resolved the problem, and now he's just given up (As yet we've not paid the bill, and as far as I'm concerned he can whistle for it). Also, to add to our woes the boiler keeps tripping out randomly when we turn on the hot tap.:mad: :mad: :mad:

I've noticed a couple of things which I think might be related, but then I'm not a boiler engineer. Firstly, We've noticed that the upstairs rads are giving off a low heat when the shower is running, it's almost like the hot water is plumbed into the heating?? (All of the supply pipes are getting warm to touch, we're not just imagining it!) we've also noticed that when turning on a hot tap, the pressure in the heating system goes up very slightly (one mark on the dial, whatever that relates to). One final thing to note is that it sounds like there's air in the system, When turning on a hot tap it spits and splatters and when stood next to the main supply pipe in the bathroom it's kind of hissing and bubbling as it flows.

Any advice would be greatly appreciated, as it's driving me insane. I used to turn on the shower and get a full on massage, now I'm lucky if i can rinse the soap off.

EliteHeat

The first thing to point out is that unless the boiler is a condensing model it is illegal to relocate it.

Next, combi boilers are entirely dependant on the incoming mains water pressure and flow rate. Where is the new mains supply in relation to the old location?

The fact that the heating is coming on when the boiler is supposed to be providing hot water points to a faulty diverter valve or diaphragm.

The boiler tripping out will not be happening randomly, it happens for a reason.

It normally happens when there is a demand for heat (hot water or central heating) or shortly after the demand has ceased – e.g. the hot tap is turned off. The two scenarios indicate differing problems, so which one is it?

It is also not clear if your muppet of a plumber is also your muppet of a boiler engineer, perhaps you could clear this up.

Canucklehead

EliteHeat wrote: »

The first thing to point out is that unless the boiler is a condensing model it is illegal to relocate it.

Good morning: A CORGI engineer can relocate a non-condensing boiler but only under certain conditions... for example...
1. Need to ascertain whether the appliance complies with Gas Regs.
2. If it is an older appliance without CE mark it needs to have a data badge with gas type and pressure details
3. Consider suitability of the appliance
4. Advise customer of CHeSS requirements (basic and Best practice)
5. Installation must be notified ...homeowner will receive a 'Declaration of Safety' certificate

'It is acceptable to ADL1B to relocate a previously used appliance within the same property providing it complies fully with the requirements of GSIUR.' Source: Gas Installer Issue 127

The question is as a CORGI installer would you feel comfortable signing off a previously used appliance if it complies to Regs?:think:

For full details see Technical Feature 'Relocation,Relocation' in Gas Installer June 2006/Issue 127

HTH

Canucklehead

P.S. My OH, Corgi Guy, concurs with EH's diagnosis. Let us know how you get on!

Pauls

Thanks for the info, We did have one guy say he couldn't move the boiler but we just thought he was trying it on. He didn't even look at the boiler before diving in with his sales pitch. Could this mean we have problem getting things signed off by the building regs? Do we need any paperwork from the boiler bloke? (Yes, muppet plumber and muppet boiler bloke are one and the same!)

Anyway, the boiler has simply moved from one side of the wall to the other, though the mains feed does now goes up into the ceiling space and then back down on the other side. The mains pressure was measured at the furthest point from the supply and I'm told it was 5bar at this point.

The boiler trips at the start of the supply, when we turn on the tap. I had to reset it 4 times this morning before I could fill the kitchen sink.

Do I still want to get worcester out to take a look at it, they've quoted a standard charge of £185, rising to £245 if its the heat exchanger thing?

EliteHeat

The boiler symptoms don't sound like the (secondary) heat exchanger to me. To be honest you would probably be best getting WB out. At least they ought to have the parts with them to enable an immediate fix.

As it's a standard efficiency boiler, the pragmatic approach to the relocation is just to forget about any documentation.

The water supply problems are odd. Are you getting the same flow rates out of hot and cold taps running individually? are two cold taps capable of running at the same time, albeit at a reduced rate?

Pauls

No problems at all with the cold pressure, you could quite happily turn on every cold tap in the house

As for the hot pressure it's pathetic, even when it's the only tap running in the house. I reckon it must be half what it was prior to the move? Could it be that we're losing pressure due to the heating thing?

EliteHeat

No, they are not directly related. It is odd that you should have fantastic pressure on the cold side and rubbish on the hot - that points towards a constriction either before, in or after the boiler.

The path through the boiler is very simple, it really just goes through the heat exchanger. It's hard to see that this could have become blocked during the boilers relocation.

All combi boilers have a cold water isolating tap on them, the obvious thing to do is to check to see if this is fully open. It will be on the underside of the boiler.

If this is OK, I would isolate and detach the cold feed into the boiler and check to see if there is a filter of some sort that has become blocked.

Next I would detach the hot side connection, re-attach the cold side and with the power off turn the cold isolating valve to fully open whilst holding a bucket underneath the boiler. If the pressure and flow rate are good then your problem is downstream of the boiler. If the reverse then a quick check of the cold pressure at the boiler will determine if the problem is upstream from the boiler or within the boiler itself.

If the flow through the HE is really low, the boiler will not modulate down enough to cope with the lower volume of water. Under these circumstances it may be possible that it is overheating, in any event the excess heat is dumped to the central heating side so it is by no mean certain that you have a duff diverter valve after all.

The water side sounds like the key to all your problems to me.

Pauls

Just to give you an update we've had a Worcester engineer out to it, and basically the guy that moved it was a complete moron and hadn't turned up either the gas or water pressure to appropriate levels. The lack of gas pressure was causing the boiler to trip, and the water pressure gives a pretty obvious answer to the other problem.

Thanks again for your input
:beer:

Canucklehead

Good morning: The installer who repositioned your boiler should be reported to CORGI http://www.trustcorgi.com/complain/installer/reportregisteredinstallers.htmx

Has the installation been notified i.e. have you received a Declaration of Safety certificate?

Canucklehead

Pauls

Hi again,
Still got problems with the heating warming up when the shower is running, both the DHW & CH flow pipes are getting red hot when the shower is running, I guess this is the diverter valve you guys previously mentioned?? Might need to call worcester back to say we still having problems, hopefully they won't charge us another £185 for the priveledge.

Anyway, we've now also noticed that the moron has put the TRV on the wrong side of one of the radiators (ie on the return, not the flow) and he's put a towel radiator upside down. We'll certainly be reporting him to Corgi, and he can sing all he likes for his last payment. :mad: :mad: :mad: :mad:

Oops, forgot to mention we've not had a certificate yet. I suppose that means we'll struggle to get our paperwork from the council to say that everything comforms to regulations.

I might start a campaign for a 'Report a dodgy thieving cowboy' board, to stop people like him ripping anyone else off

Canucklehead

Hi

Most TRVs will work in either direction have a look and you may well see an arrow ,on the body of it ,pointing both ways.
Wouldn't like to comment on the towel rail though!

Corgi Guy.