Hot water but no heating

Hi, I hope you are able to help...

We have a Boilermate 2000 with a Baxi 400 heat only boiler (brand new). We currently have good hot water but no heating.

We had the new boiler installed a few weeks ago because the boiler kept locking out - this was identified as being as a result of a very old boiler (20 years) and a blocked pipe was found. Our system has been flushed.

Since the boiler has been installed heating and water has been working well. However, over the past few days we are no longer getting heating.

The boiler is set to output at 80c and is on all the time. On the timer we have heating to be on during the day but off overnight.

The PCB shows =On and reads 58, 50, 58 when you circulate through the three readings.

In the morning when the heating switches on, we find that the heating works for a short while (to make the radiators half warm) but then switches off again after probably 10 minutes.

I understand that the Boilermate needs to get to 60c for the heating to turn on - hence why it isnt working.

What is stopping the Boilermate being heated further? The boiler keeps being asked for heat and fires up every 5 minutes or so and then runs for a few minutes (it doesnt lock out).

On the PCB, the bottom two lights are on all the time and the third (heating) switches on occasionally when the tank manages to reach 60c, before turning off after a few seconds.

The heating pump can be heard running for a short period of time - i have checked that it is not jammed.

The left hand pump runs constantly.

Any ideas!?

If the bottom two LEDs are one (bottom boiler 2nd up boiler circ. pump) then the system is trying to get more heat into the store which at 58 it should be doing. Is the boiler actually hitting 80 degrees before it cycles off? I know it is brand new but you never know. You should not be able to hold the feed pipe from the boiler to the store if it is hitting 80. If it isn't then the boiler thermostat may be the issue. If it is then there is not enough flow through the store to exchange the heat. If the system is making gurgling noises then there may not be enough water in the store (the feed from the header can get blocked , wire coat hanger can fix apparently). The issue is heat from the boiler is not being transferred to the store so that is the line of investigation, worth checking the boiler pump speed it should be on max. Let's know what you find. Regards Murray