14 years is a really good run and you should not feel bad if you choose to replace it. I had a Heart 458 which had a fan fail but I found a replacement and got it running again. I then found a deal on a TSW (PSW) inverter and I took out my working 12 year old Heart and threw it away. It was only a matter of time and I would rather replace hardware on my schedule than being forced to replace the hardware at the least convenient moment.