Very High Gas Bill - Using a Baxi Boiler

[bsr2005]

Hi,

Wondering if anyone can help.
Have a Baxi boiler in a house I am renting out. Tenants complaining of very high gas bills.

They also saying that when they turn on the hot water-- the central heating also goes on very hot. They have said that the thermostat is on 15c and that the switch with CH is turned off.

Any ideas as to why the CH is coming on when only the hotwater switch is on ?

In terms of getting the Baxi boiler (back boiler inside chimney breast) serviced - would that solve the problem? Not many tradesman are keen to have a go...

Any advice very much appreciated.

 

[Agile]

A back boiler is very inefficient at about 55% and there is clearly a fault in the system too.

It should not be difficult getting a competent CORGI engineer to repair it if you must. Might cost £100-£300.

You should also have a Gas Safety Certificate when renting. It sounds as if you may not!!!

The correct full solution is to have a nice new condensing boiler and cylinder with TRVs and full controls. That will cost about £2000-£3000.

All tenants complain about paying bills and they probably complain about your rent as well.

Most landlords dont like spending money on their rented properties and clearly your heating system is well out of date and you may not have the required safety certificate either.

Tony

 

[gasright]

The high gas bills could be due to a build up of products around the heat exchanger in the back boiler which is causing the unit to work harder thus use more gas.

If the tennants are previously used to a combi boiler then yes they will feel the pinch when compared to a back boiler.

My advice is to have the back boiler stripped down and thoroughly serviced. And take it from there.

I think a back boiler is 70% efficient whereas a typical combi is 90+% efficient.

Ps. If you have a back boiler in a tennanted property ALWAYS have a carbon Monoxide detector fitted

 

[bsr2005]

Thanks for the advice guys. I had a gas safety certificate and service done 2 years ago (I need to get it serviced again, I know),
I'd rather not fork out an arm and leg and get a new combi installed. I guess my only route is to get this one serviced....
Have called a number of CORGI registered guys who don't seem keen to come and service it... they all say that I should install a new boiler as the BAXI's
are more trouble than they are worth. Obviously they want me to spend more with them ...

And yes, I do have a Carbon Monoxide detector in the vicinity.

 

[Agile]

Gas Safety Certificates are required by law and only last for 12 months.

Because of the potential dangerousness of back boilers they need a PROPER service every year which takes about 1.2 hours! More often if there are furry animals or shaggy carpets.

You need an electronic CO alarm which makes a loud noise not just an indicator spot.

I so have to say that your careless disregard for the safety of your tenants is really quite worrying. Many of the deaths by CO poisoning are from back boiler installations.

Tony

 

[andy.budgell]

Sounds like the 3 port valve isnt working correctly or is stuck.
Probably due to motor failure.

This used to happen to my system. £15 new motor.

 

[DP]

A fair number of back boiler installations are Gravity HW and pumped CH systems. Three port valve is exception rather than the rule.

As has already been suggested, get the boiler stripped down and serviced properly. This means the firefront is removed, gas train removed, heat exchanger swept with a brush (top to bottom and front to rear to remove combustion debris), clear/ clean burner, clear boiler base of debris and reassemble.

Do same to fire.

Carry out flue and spillage checks. Also test burner pressures.

Now verify why heating is coming on. Possible cause is programmer wiring incorrect. Normally (for gravity hot water system) hot water zone would activate to HW program, but calling for CH will activate HW zone as well.

 

[bsr2005]

In response to Agile.. I have an electronic Carbon Monoxide device.
Will definately get a Gas certificate renewal done asap. These tenants have been in for a number of years so totally forgot about it to be honest.

If I go for the British Gas monthlyt subscription service, do you think they'd sort it out? Infact is it worth going with them?

 

[Agile]

I am not sure if BG will still take on old BBU installations.

Apart from the need to get a proper annual service they are very reliable and a BG service contract would be a waste of time.

However they are very inefficient and a modern condensing boiler would save the tenants about 30% or more on the gas consumption compared with a BBU even if it was working properly.

Tony

 

[giblets]

If I go for the British Gas monthlyt subscription service, do you think they'd sort it out? Infact is it worth going with them?

Unless the boiler is under 10 years old I don't think BG will be interested TBH. But you could always try.

 

[bsr2005]

Yep.. thats what I thought as well. Have been told that they shy away from old boilers.

If I do decide to put in a new boiler, would I be able to do so using the same pipework that goes into the BAXI ?

Was thinking of placing the boiler where the Hot water tank is.

 

[gasright]

i have an uncle that works for British gas as a service tech.

From what he says BG will not service a BBU and if they do they will try to condemn the system asap.

My advice is to get the unit thoroughtly serviced and a CP12 issued every year as a rule, and also budget for a new condenser system.

the last thing you want is for your tennants to call out Transco and have them condemn your system due to it being unsafe.

Don't be one of those landlords that couldn't care less and waits for an incident before doing something.

 

[gasright]

i have an uncle that works for British gas as a service tech.

From what he says BG will not service a BBU and if they do they will try to condemn the system asap.

My advice is to get the unit thoroughtly serviced and a CP12 issued every year as a rule, and also budget for a new condenser system.

the last thing you want is for your tennants to call out Transco and have them condemn your system due to it being unsafe.

Don't be one of those landlords that couldn't care less and waits for an incident before doing something.

 

[bsr2005]

Absolutely agree ... Will get the monster serviced and Gas Certificate issued ...

 

[Slugbabydotcom]

Because of the potential dangerousness of back boilers they need a PROPER service every year which takes about 1.2 hours! More often if there are furry animals or shaggy carpets.

Tony

I find the number one culprit for causing back boilers to soot up is actually Laminate floors. The dust blows around until it gets near the boiler and is drawn into it.
Shaggy carpets actually act in your favour and filter the dust before it gets to the bbu.

Pets take up the number 2 slot

Ironing in a room where theres a back boiler is third.