BAXI BERMUDA BACK BOILER ISSUE

[Belboz]

Sorry this takes a bit to explain but I will try and keep it short.

Last weekend, water started leaking from the bottom seal in the central heating pump. Called plumber and I drained the system. Plumber came and fitted new pump (plus two new isolating valves above and below the pump) Re-filled system. Cylinder filled with hot water fine the next day when hot water was switched on. That evening, came home from work and tried to get rads to work. First rad in the system got hot but all other rads were cold. Bled rads and all have water inside. Checked F&E and all appeared okay. Guessed there may be an airlock somewhere in the rad pipework. Off to work the following day [intending to try and sort the rads out that evening] and, when I came home, 'er indoors' told me there was no hot water!

As it had been very windy, checked to see if pilot light had gone out. Nope - pilot okay. Switched on for hot water and back boiler fires up then cuts out after only a few seconds.

Called plumber in case he knew where the fault may lie (I assumed it wasn't the boiler hence why I called the plumber ) He suggested an airlock and to run mains water back via the draincock on the lowest radiator to try and clear it.

Now it could be sheer coincidence but, given the boiler worked fine for hot water on Day 1 (it didn't cut out after only a few seconds like it did on Day 2) any ideas as to the problem please?

Any ideas would be greatly appreciated.

Thanks

 

[twgas]

Check the new pump valves are open

 

[Belboz]

Mick,

Stupid question but how would I know?

The plumber replaced the old valves (which has a screwdriver slot to open/close then - one was seized) with gate pump valves (which have no 'wheel')

Is there a way I can tell if they are open or closed?

Would the first rad still get hot even if the valves were closed?

 

[twgas]

Small spanner on the spindle, if they don't turn one way try the other,
The one rad might get hot if the valve(s) are just cracked open.

 

[Belboz]

Thanks Mick.

I will give that a go and see what happens.

 

[Belboz]

Valves are now open. Switched water on. Back boiler made no noise (it normally makes a 'whoosh' when heating/water switched on)

No hot water/no heating.

Guess I need to call out a boiler engineer???...............

 

[Hugh Jaleak]

Do you have the option to have the Central Heating on without the Hot Water being on?

 

[twgas]

Is the pump running?

 

[Belboz]

I can switch the heating on separately from the hot water. Trying either individually or both at once has the same result - the back boiler makes no 'whoosh'.

The pump clicks on and runs when either (or both) are switched on.

I am assuming that the new pump has been correctly wired when the new one was installed (would that make any difference?)

As I said, the hot water worked fine the day the pump was fitted albeit, later in the evening, the rads wouldn't heat up (only the first one)

The back boiler was working with the usual 'whoosh' that day but no longer makes the noise.

I am guessing I am unlucky enough to have the pump go and now the boiler has developed a fault.

I haven't tried using the mains to try and clear any airlocks yet as I am thinking that wouldn't resolve the issue with the boiler. Or am I wrong?

Thanks for all your advice.

 

[Hugh Jaleak]

Still sounds like a circulation issue. If the water isn't circulating from the boiler then the water within the boiler could be up to temp therefore boiler wont fire. Do wonder if the new pump has been fitted right way around..... Has the boiler fired ok since the new pump was fitted?

 

[matt1e]

It has probably overheated due to the pump valves being closed and Its overheat stat now requires resetting

Matt

 

[Belboz]

As far as I could see, the valves were open on the pump. We had hot water on Day 1 (after pump was fitted) - a full cylinder - and, therefore, the boiler was working okay that day.

Tried to get rads working evening Day 1 and wouldn't heat past Rad 1. All bled okay but still wouldn't heat rads past Rad 1. Guessed it was an airlock.

Went to work next day intending to 'cure' airlock on evening of Day 2. As stated, wife said no hot water on Day 2. Checked pilot on back boiler - all okay. When calling for heating or hot water, boiler fires ('whoosh') then cuts out after only 5 or 6 seconds.

As I said, this could just be a very big coincidence and the boiler has developed a fault around the same time as the pump seal failed.

Not convinced of that though.

As a 'thicko', I am guessing the boiler not firing has something to do with having drained the system and replaced the pump.

Can't figure out what though.

I know I should be calling in an 'expert' but thought I would seek advice here first in case it is something realtively simple which I can rectfiy.

If not, Christmas cash will have to be spent on a heating engineer....

 

[Hugh Jaleak]

The 'whoosh' is the boiler firing. However, once the water inside the boiler is heated up and reached temperature the stat on the boiler will switch boiler off. The pump needs to be circulating to move the heated water out of the boiler and around the system, allowing the boiler to continue firing until system indicates it is satisfied.

As this issue seems to have coincided with the new pump being fitted I would call the plumber back. I do wonder if the cylinder had remained hot from the previous day, and the system has not worked correctly since the new pump was fitted...

Can you get access to the pump and pipework easily?

 

[Belboz]

Hugh,

The water dripping (through the light fitting into the kitchen below) was noticed last Sunday afternoon. As soon as I realised, I switched off the heating/water controls and unplugged the electric supply. We used what was left of the hot water in the cylinder on the Sunday (so as not to waste it!) I got hold of the plumber last Monday and arranged for him to come first thing Tuesday morning. Monday evening, I drained the system down ready for him to replace the pump on the Tuesday. Pump replaced Tuesday and I went off to work. There was no hot water in the cylinder before he replaced the pump. Tuesday evening there was a full cylinder of hot water. Tried to get the rads on (blah..blah) The rest you know.

Called the plumber back and he came on Thursday morning. Boiler issue noticed and he advised it may be an airlock and to try and cure it with mains pressure. If not, he said, I need to call a heating engineer.

Yes, I can access the pump easily as it sits in front of the cylinder alongside the motorises valves and pipework.

 

[matt1e]

calling for heating or hot water, boiler fires ('whoosh') then cuts out after only 5 or 6 seconds

So it is firing then?
I was under the impression that t was no longer firing?

I can switch the heating on separately from the hot water. Trying either individually or both at once has the same result - the back boiler makes no 'whoosh'..