Any plumbers/boiler experts on here ?

[Biggs]

I've got a Biasi combi boiler here that keeps locking out for some reason, so I'm not getting any heat or hot water. When i press the reset switch, it seems to run fine,well it is on anyway, just not sure if its running as it should as i don't pay too much attention to it when it's running correct, but then I'm only getting hot water and no heating.

The water doesn't get as hot as it should but it's hot enough to have a shower.

Is there anything else i can do/check, as there is only really one button (reset button) to press ?

There are 2 dials with different modes to select but i don't want to cause more problems.

Cheers

[Penfold aka The Dealer]

Speak to JRP mate... very helpfull

[clee]

Probably the water pressure has dropped .There will be a tap and pressure gauge in line from that .Off the top of my head 1 to 2 bar should be seen .

[Biggs]

Speak to JRP mate... very helpfull

Cheers

[Biggs]

Probably the water pressure has dropped .There will be a tap and pressure gauge in line from that .Off the top of my head 1 to 2 bar should be seen .

Its sitting at 1 bar which it has always done

[Os8472]

I had a similar issue with my boiler, 3 gas engineers later I still had no heat, so I took the outer case off myself and spotted the filter pot for the drain pipe was full, I removed it, emptied it and refitted, now have toasty hot water and heating

[TNT ANDY]

I had a similar issue with my boiler, 3 gas engineers later I still had no heat, so I took the outer case off myself and spotted the filter pot for the drain pipe was full, I removed it, emptied it and refitted, now have toasty hot water and heating

Sparkies rule

[westy94]

possible heat exchanger is blocked/restricted causing it to overheat and cut out. not really a diy job though bud alot can go wrong. but without seeing it hard to diagnose really, combi wont fire at all if pressure to low so wont be that.

[Big Steve - Raider]

I had a similar issue with my boiler, 3 gas engineers later I still had no heat, so I took the outer case off myself and spotted the filter pot for the drain pipe was full, I removed it, emptied it and refitted, now have toasty hot water and heating

Go-On Ipswich!

[Ian S]

I think 1 bar might be about the minimum for a combi. If it drops further at peak times such as early evening and weekend mornings that might stop hot water working, for those periods at least.

But the heating should still work OK I assume.

Is it a condensing boiler as Os8472 assumes?

Is there switched live being applied to the control box from the room thermostat and timer when they are both set to 'on'?

Does the pump start and keep going circulating the central heating water?

[JRP]

Hot water issue.

On a combi, could be a simple thing like a thermistor slightly out, possible that the plate heat exchanger, the smaller sardine tin looking thing could have some muck on the heating side, causing the boiler to shut down thinking its reached its temp and exceeded it, if not it would modulate givng a constant heat. Possible if its an older model its a duel heat exchanger errrgggghhh....

Biasi is a basic copy of glow worm hxi's etc all a tad rubbish,

How the heating side of things?

if the heating is working then things like condense trap etc can be left alone, although check to be on safe side, H/W demand runs on a higher rate more often than heating creating more condense.

if you check round your house too, all to often a mixer tap causes issue on hot water, were the cold pressure is to great and it can back fill on a weak tap. causing boiler shutting down etc.

assuming nobody has fiddled with it, and co2 emmisions are ok its basics we are looking at.

a boiler G/C number would be good, should start 47-...-..

TBH with no model info etc its hard to know where to start.

Power Y/N
Clock on Y/n
Power from clock to boiler Y/N

at least its a combi so no running round the airing cubord and valves etc although wireing on that is a dodle.

ANY ERROR codes? or just plane simple overheat?

[JRP]

Heating is an issue too? Is pump running or is it sluggish, does sound like its not clearing the heat. or somthing is a tad out of calibration.

Joys to the world

Ian are you confusing Gas pressure with the water pressure in his heating system.. The water in the heating system is sealed and should not drop very often, and will move up and down as the water expands and contracts heats/cools.

If its gas pressure your meter should be 21 +/- 2 mlb working presure,

standing pressure will be greater dont get confused.

the issue of heavy useage times is some what ancient now. maybe maybe xmas day when turkeys are being cooked lol.

[westy94]

If its only all getting Luke warm heating and hot water as I said before top two faults heat exchanger clogged with scale or pump faulty again due to prob getting glogged with oxide but I would be checking both heating and hot water exchangers for cold spots!!

[JRP]

If its only all getting Luke warm heating and hot water as I said before top two faults heat exchanger clogged with scale or pump faulty again due to prob getting glogged with oxide but I would be checking both heating and hot water exchangers for cold spots!!

Are your rads cold at the bottom and in the middle? water quality is the issue normally as westy says.

just hope sombody looks at it that uses a methodical mannor to asses it, basis first.

Good luck biggy biggs

[Biggs]

Thanks for the replies so far but tbh I don't have a effing clue what you are talking about. I'm going to pop out to the garage and take a few pictures of the boiler if you think it might help diagnose.

It's more a problem with the heating rather than the water. I can get the water hot by resetting the boiler, but I'm getting no heat at all through the radiators. Thermostat controller is fine as far as I'm aware, although the batteries were recently changed (heating has worked since this)

[Ian S]

No I meant water pressure dropping. The combi won't come on if it's too low. Here, I've seen it as low as 0.25 Bar some Sunday mornings. Basically, the hot water doesn't work at periods on weekend mornings. Essex water have upgraded the mains in this area, and are still doing.

I've not measure the gas pressure.

My heating went lower and lower then stopped over a couple of months a couple of years ago. I found it was the pump clogged with black sludge. Set hard. I spent an hour with a small chisel digging it all out of the impeller. Took apart the boiler outflow pipes and cleared them too as they were nearly fully occluded. Was fine after that.

Many of my 1967 rads are cool at the bottom. I have a heat only boiler and Main Seven or Mersey water heater.

[Biggs]

The lights on the far left of this picture flash red green and red (left to right) when it needs resetting

[westy94]

Thanks for the replies so far but tbh I don't have a effing clue what you are talking about. I'm going to pop out to the garage and take a few pictures of the boiler if you think it might help diagnose.

It's more a problem with the heating rather than the water. I can get the water hot by resetting the boiler, but I'm getting no heat at all through the radiators. Thermostat controller is fine as far as I'm aware, although the batteries were recently changed (heating has worked since this)

If it is just the heating I would put money on it being the pump or most Likley the heat exchanger both of which are not really a DIY job fix unless you really handy with tools, get it wrong trying and you will have a lot bigger probs mate .

[Biggs]

If it is just the heating I would put money on it being the pump or most Likley the heat exchanger both of which are not really a DIY job fix unless you really handy with tools, get it wrong trying and you will have a lot bigger probs mate .

Thanks for the reply

[JRP]

That biasi is a copy of the ideal mini. Awful boiler. I had one in my old house for about 5 mins. Chances are that rubbish wilo pump bottom right hand side ( inside) is buggerd. The dhw plate h/e on that is only held on with 2 Allen bolts at the back of the manifold with the diverted valve. Pop it out to clean, new seals required/ o rings.

Prob all just crappy water on heating side.

Hard or soft water area?

[JRP]

Biggs. Do you have a wireless room thermostat? Just thought it may have lost connection to the reciver.

[JRP]

Pump is for reference bottom right Biggs. Is it running?

[Ian S]

When it used to be warm in summer and my Grundfoss selectric pump was off for months, it would seize. If I recall correctly I'd have to undo the chrome screw and give the end of the shaft a sharp tap with something. That would free it and then would start to turn.

[JRP]

When it used to be warm in summer and my Grundfoss selectric pump was off for months, it would seize. If I recall correctly I'd have to undo the chrome screw and give the end of the shaft a sharp tap with something. That would free it and then would start to turn.

Careful on a sealed system, especially on a wilo etc you might get very wet if shaft has cone loose from impeller.

[Ian S]

What make would you suggest as a new boiler now if I needed to get one? Vaillant? Are they reliable or am I better to keep the early 1990's Potterton Profile going? I've repaired the electronics board and last winter I had to bodge repair the fan bearing which had fallen apart. I don't want to buy into an expensive modern pile of crap which will fail very expensively after a year or so and require new extortionate price parts. The Potterton is making a buzzing sound, could be the fan bearing again, seemed to be not available as a spare, if at all.

[TNT ANDY]

Had a Worcester Bosche 5 yrs - no problems.

[JRP]

I have a profile 80e pm me if you need a new board remember Ian it's positive pressure a profile, so a good case seal essential.

As for new boilers either a valiant or Worcester

[Biggs]

Thanks for all the advice, had a guy come round today and he sorted it out.

Don't know what was wrong tbh but there was no charge as this guy had previously serviced the boiler a couple of weeks ago. Must of been related to that somehow, I don't really care as long as I've got some heating.

Anyway thanks again for any help

[JRP]

Thanks for all the advice, had a guy come round today and he sorted it out.

Don't know what was wrong tbh but there was no charge as this guy had previously serviced the boiler a couple of weeks ago. Must of been related to that somehow, I don't really care as long as I've got some heating.

Anyway thanks again for any help

Lol I bet he shut a return or flow pipe

[TNT ANDY]

I have a profile 80e pm me if you need a new board remember Ian it's positive pressure a profile, so a good case seal essential.

As for new boilers either a valiant or Worcester

GY Council fit both of those as standard, and they don't muck around with specifications, it's not their money, so what the hell right?

[andybond]

Can I hijack this thread with boiler questions ?

I have a saunier duval ( its ****e from what I read )

Keeps loosing pressure.

I have changed the 3bar pressure reg thing that ejects water to the external pipe.

Only looses pressure when +ive pressure and running C/H and H/W

Any ideas ?

[JRP]

Can I hijack this thread with boiler questions ?

I have a saunier duval ( its ****e from what I read )

Keeps loosing pressure.

I have changed the 3bar pressure reg thing that ejects water to the external pipe.

Only looses pressure when +ive pressure and running C/H and H/W

Any ideas ?

Yeah, chances are its the expansion vessel. It acts the same as the header tank on an open system. It takes up the expansion.
It will be a red tank with a shrader valve, it needs to be charge to just over 1 bar. If it looses its charge, your heating water has nothing to expand on, and there for when reaching 3 bar it dumps it out that safety valve you changed.

Pop a hose on open and let pressure off, the. Get foot pump on red vessel and pump it back to a bar. Be sure the drain taps open on th ch system, or you will get a faulse reading. Hope this helps.

Red tank may be behind the boiler against wall, or internal.

Ring me if you need, easy fix no parts should be needed

[JRP]

It needs to be 1 bar AIR the vessel. Sorry I should have made it clearer

[andybond]

Wow. Thanks. ill look into that tomorrow evening.

[TNT ANDY]

wow - this is the hottest topic atm LOL. The RTOC love spreads ever wider.

[rikki GT]

What make would you suggest as a new boiler now if I needed to get one? Vaillant? Are they reliable or am I better to keep the early 1990's Potterton Profile going? I've repaired the electronics board and last winter I had to bodge repair the fan bearing which had fallen apart. I don't want to buy into an expensive modern pile of crap which will fail very expensively after a year or so and require new extortionate price parts. The Potterton is making a buzzing sound, could be the fan bearing again, seemed to be not available as a spare, if at all.

what model profile is it? (if its the boiler i'm thinking of it will have a lower grey cover, it should have a data bage visable on there once removed with a model name and number and a G.C number 41-...-..) i'm pretty sure you could still get hold of the full fan assy if needed... as well as pcb's(elec board), gas valves etc

if you are going for a new boiler, either sticking with a conventional system boiler or swapping to a combi, as jrp said, i would go with worcester or vaillant. just make sure the condensate pipe is fitted with minimal chance of freezing up as that has been the biggest problem with recent winters. internally to a sink/washing machine drain is best or if not possable minimal outside run with a decent drop on the pipe.
unfortunatly new boilers are more expensive to fix if they do go wrong as they have become more complex with efficency. i guess you have way this up with the saving on ur gas bill. i have a worcester greenstar combi 2006 and have never had a problem with it, but have seen faults on the same boiler in work after much shorter times, as with anythin electrical/mechanical it can and will go wrong some times.

[Matt Cole]

I have just specified a load of Baxi's which are really good. Get a good controller/room stat too. For the condensate get a small trace heating system on an external temp sensor. Job done.